There are lots of pest and disease issues out there in garden land and many solutions to control them. My close friend, Lynda Hollup has figured out the best beer to use in controlling slugs and snails? Lynda of Huntington, West Virginia, told me she finds that Old Milwaukee is the best beer to use in pie plates. With that being said, slugs and snails are a menace to our gardens and I'm not sure what kind of beer is best to use - whether it's homemade or store-bought. Perhaps I should ask the "Chuckster," who by the way wanted to know if I liked to eat escargot (snails)? I made it clear to him that I was adverse to these slimy creatures who like to come out at night munching on the underside of leaves. Their favorites are basil, lettuce, marigolds and hostas- especially hostas. They love cool, damp, dark areas, not warm, dry spaces. I'll leave it at that.
So folks, as I just stated we all got pests and diseases in our gardens and life. The first thing to do is identify the problem. It's not that difficult with all the pictures of insects and diseases pictures available on the web. You can go to the Pest Control Library of the National Gardening Association or Gardening - About.com - under insects and diseases. You can contact your local Master Gardener Helpline or the Plant Diagnostic Clinic associated with your state's land grant university.
If you're a new gardener, you may to simply to check with a neighbor or a gardening friend to help you in your quest. And remember, it's not the end of the world when you find a potentially harmful insect. Keep in mind that 95 percent of garden visitors are either helpful or harmless.
It's fun to put on your inspector cap and go out looking for the culprits. Once you've identified them, go online to see their pictures. It's interesting to see them in full color on your computer screen and even more so in the garden. If there are only a couple of troublemakers, you don't have to do "nothin", or if they begin to get out of hand, you can control them with an assortment of organic pest-control strategies, including parasitic wasps, row covers, soap and water, sticky traps, and organic pesticides.
Luckily, as gardeners, we are not relying on the food we grow in our gardens for our sustenance and can often accept more damage than a commercial grower. Losing a good part of a tomato crop to a farmer can be devastating, but not as much to a home gardener. At the same time, some many gardeners rely on their gardens to produce a lot of food for the summer and cold months.
And please remember that you don't want to kill the beneficial insects including bees or butterflies with a harmful pesticide even if it's an organic spray. You can handpick caterpillars or use floating row covers to prevent adults from laying eggs.
In my forty years of gardening, I've found only a few vegetable insects and diseases that have caused major damage to my crops, like the Colorado potato beetle, Japanese beetle, cucumber beetle and Mexican bean beetle. Late Blight on potatoes and tomatoes is a serious fungus disease. New ones are coming on the scene with global warming.
The "Chuckster" just commented, "Why do you plan on writing about pests and diseases if they aren't such a big deal." My response: "Perhaps you're right and I'm just obsessed with all this stuff. On the other hand, it's good to know what's out there, especially with all some pests and diseases that have come our way in the last few years, like the late potato/tomato blight which made a resurgence three years ago and had been sighted in Vermont in 2013. Actually, it has always been a problem in Vermont, but it used to show up at the end of the season. Now we are seeing it earlier."
Fruit and berry diseases are an entirely different matter. They are much more difficult to eradicate. Here are some of the major ones.
Insects: Tarnished Plant Bug, Leafminers, European Apple Sawfly, Mites, Plum Curculio, Apple Maggot, Codling Moth, Leafhopper, Aphids, and Borers. Birds can be a major problem for berries and squirrels can ravage peaches.
The newest disease for soft fruits - blueberries and raspberries - is a tiny fly called the spotted wing drosophila. The fly lays it eggs in blueberries, raspberries and other soft fruits and a few days later, the fruit begins to wrinkle, mold and get spots.
The spotted wing drosophila is just one of many foreign pests that have invaded Vermont and other states because of the changing climate. The hemlock wooly adelgid threatens to wipe out the state's hemlock groves and the emerald ash borer beetle could wipe Vermont's ash trees. The climate is getting warmer along with lots of rain in spring and more droughts in summer. According to Jeffrey Dukes of University of Massachusetts, insect metabolism roughly doubles with every increase of 10 degrees Fahrenheit. (2009) As an insect's metabolism increases, it grows faster, eats more, and mates more often.
Diseases: Apple Scab, Powdery Mildew, Black Rot, Fire Blight, and Cedar Apple Rust.
* You can read more about Fruit and Berry Pests and Diseases in The Woodchuck Returns to Gardening in the chapter "Fruits for the Home Orchard."
Worm wiggled into an apple
Worm wiggled into the core
worm wiggled out of the apple
I just can't eat anymore
If you were to take a tour of a fruit orchard in spring, you might find yourself getting wet under a warm shower. You would also most likely find thousands of beautiful white blossoms and lots fungus spores floating about while the bad buggers are having sex and the females are leaving their eggs on the fruit and on and on. I didn't mean to forget all the wonderful insects and bees pollinating the fruit trees.
Growing apples, pears, plums and peaches can be tough because there are so many insects and diseases that can harm the fruit. Apples and peaches are the most fungicide laden fruits besides strawberries. The main fungus diseases are apple scab, cedar-apple rust, fire blight, powdery mildew. The main insects are apple maggot, codling moth, and plum curculio.
A scabby apple spray poem entitled, "Fungus Among Us."
The first spray of spring is applied at greentip,
when the apple buds first show green.
The second spray occurs when the blossoms begin to display pink but are not yet open to be seen.
The third spray is after petal fall
and the fourth is in a fortnight after all.
The fifth may bring no more
depending on the sun and rain and the spore.
Apple Scab - Scab is particularly prevalent in the Northeast with its moisture filled climate. Organic orchardists would advise you to choose scab free apple trees such as `Honeycrisp' and `Liberty' which are very popular in organic circles, both because of their taste and resistance to scab. `Pristine' is also a scab resistant apple as are `Williams Pride' and `Gold Rush.'
The scab is caused from a fungus that infects leaves and fruits. This disease causes dull black and grey brown lesions on the surface of fungal leaves and fruits. Apple scab infections on leaves fall to the ground and spores from to infect new leaves. Rake the leaves in the fall in your small orchard. Abundant rainfall spreads apple scab. Organic growers use a sulphur/lime spray starting in spring. It will help to prevent scab infections to some extent. The problem is that fungicides such are sulphur are not systemic, that is, they don't go into the leaf. As soon as it rains, you have to spray all over again. Sulphur is only marginally effective in certain seasons, such as in 1998, when it rained constantly through the summer. Many apple crops were lost due scab that summer.
Plum Curculio - This pest is a true weevil and is notorious for destroying apples, pears, peaches and other stone fruits if left uncontrolled. The other biggee is Plum Curculio-(PC). The organic spray of choice is rotenone or what some call derris, a root derivative insecticide. It is rather expensive and not always effective as it breaks down immediately. What the plum curculio does is lay an egg in the apple and this creates scars. If the eggs hatch and larvae begin to bore into the fruit, many of the apples will drop. Where plum curculio is a problem, less than 20% of the apples will be of high quality.
Apple Maggot - The maggot lays eggs in apples from mid-July to mid-August. The larvae from the two-winged fly burrows in and feeds on apples. In orchards, maggots can be trapped by hanging several red wood or plastic ball traps in each tree by mid July and baiting them with a feeding sex attractant and sticky substance like tanglefoot. The scent in the traps attract the harmful apple maggots. Use a organic insecticide sprays to kill the rest.
Codling Moth - This pest produces a larvae and is infamously called, the "worm in the apple." And we all know what worms do to fruits. It also attacks pears. Codling moths are one of the more interesting insects to control. These "worms" you sometimes see in apples are often codling moth larvae. This insect of European origin deposits female eggs that develop a larvae that burrows into the fruit.
Pheromone traps are hung from the trees which release the female codling moths sex attractant. The male moths are drawn in by the female scent and are caught in the traps. As soon as the first male moths appears in the traps, the lady buggers have begun dropping their eggs on the apples. By counting the number of degree days it takes for the eggs to hatch, one can estimate when the larvae will appear on the apple leaves. That's the time to spray ryania, an organic insecticide. All of this activity depends on good observation and timing. If the moth counts are low, no spraying is needed. The pheromone traps need to be replaced during the season and they aren't cheap. The first generation adult females lay eggs on leaves or twigs near the blossoms; later generation females lay eggs near the fruit. The young larvae enter and complete their development in the fruit.
Another method of control is a mating disruption program where triangular white traps with the scent of the female moth are set out to permeate the orchard. The traps attract the males and disorient them to the point where they don't know where to find the ladies. These twistem like traps are also expensive, don't last too long and take lots of labor.
Fireblight - this contagious, systemic blight disease affects apples and pears, quinces, and raspberries and can destroy an entire crop. The fruits appear blackened, shrunken and cracked, as though scorched by fire.
Powdery Mildew - this fungal disease affects a wide variety of plants. Infected plants display white powdery spots on leaves and stems. It can reduce crop yields. By the way, sulphur does work well on powdery mildew and black rot.
Cedar Apple Rust - this rust occurs in any location where apples or crabapples and Eastern Red Cedar coexist. This rust can be very destructive and disfiguring to apples.
European Apple Sawfly - this insect disease was introduced in North America infesting crabapples around 1940. It overwinters as a mature larvae and pupate in the spring. The larvae feeds below the skin of the apple.
Red Mites - In general, there are enough good predators in the natural environment to control them and it isn't necessary to use any traps or sprays.
Most fruit growers go to great lengths not to apply harmful sprays, but some times it's necessary if you want to save a crop.
The biggest change in the last thirty years have been the use of Integrated Peat Management (IPM) in your small orchard. See more on IPM below.
By now, you know from what I've shared that it all `depends,' one of the "Woodchuck" principles. The vagaries of the weather, soil health, the varieties of apples grown, luck, life and the skill of the apple grower will determine the quantity and quality of fruit. You need to site a home orchard on a slight hillside if at all possible. The site needs good drainage as apple roots don't like to be wet plus you don't want to place the orchard in a pocket where there is poor air flow and the chance for early frosts.
I know you can't wait to get out in the orchard to deal with all those fungal diseases. Don't forget to count codling moths in order to disrupt all the male buggers. This type of work may not be for everyone as it takes a special kind of person who wants to work close to nature. To watch life cycles unfold and attempt to work in harmony with the land is no easy task, but it makes sense if you want to study nature and provide lots of fruits for your family.
When you have a pest problem in your vegetable patch, it makes sense to act quickly with an easy to use and effective solution.
Of course, the best solution is to control insects without using insecticides. The first line of defence are beneficial insects. They need food, water, and water just as we do. Shelter is provided by plants in your garden as well as toad houses, overturned pots, and nearly brush piles. Toads can eat hundreds of insects every night. Plus birds like to help themselves to those uninvited vegetable pests. Having shallow containers of water filled with pebbles helps to feed the insects and birds.
Mixing up the garden with vegetables, herbs and flowers also helps as does companion planting like carrots and onions. Carrots tend to ward off onion flies, whose larva burrow into the onions. If you have room for one beneficial plants in your garden make it a nasturtium. These magical plants repel dozens of insects including tomato hornworm and many types of beetles and their flowers are edible. Almost every year, I use crop rotations with green manures of oats, buckwheat, annual and winter rye. Strong smelling herbs not only draw in pollinators when they are in bloom, but they also repel many harmful insects who rely on scent to find your plants. Annual herbs like basil, in and around tomato plants ward off the tomato hornworm.
* See The Woodchuck's Guide to Gardening for more on Companion Planting.
Tomato Hornworm - they are the larvae of a large mottled tan sphinx moth that flies at night. You can pick these large green, colorful caterpillars with white side strips off the tomatoes with ease. Just don't be squeamish. Some of their natural enemies include yellow jackets, lady beetles, green lacewings and braconid wasps. Don't destroy the ones with white eggs coming out of their bodies. These are eggs of a predator and you want for control purposes.
Codling Moth - Please go to section on fruit trees for info on the Codling Moth.
Cabbageworm - The most common cabbage pests are cabbage worms. When you see those little white butterflies, take action to protect your brassicas before the cabbage worm moths lays eggs. Cabbage worms weaken plants by removing plant tissue, and they can ruin beautiful heads of cabbage and broccoli by boring inside. You can handpick the worms, exclude them with row cover barriers, or treat the worms with a Bt or spinosad.
* Bacillus thuringiensis (Bt) has been used on many organic farms for over 50 years as a microbial pest agent. It is a natural, non-pathogenic bacteriun that is found naturally in the soil. There have been concerns about some dangers associated with Bt. Go online to learn about these potential problems, such as the problem with the "inert' ingredients in Bt. People with sensitive immune systems could be affected by Bt. Bt secretes certain toxins which also could be damaging to humans in their gut.
Cabbage Looper - This is a type of cabbage worm. If the cabbage pest in question is a green to yellow-green slender caterpillar that raised up on it back as it moves, it's likely a cabbage looper. Use same methods for cabbageworm.
Corn Earworm - If you see small green worms wriggling around your corn, the chances are they're corn earworms. In small home plantings, you can open up the end of an immature ear remove the corn earworm with tweezers, and secure the husks back in place at the tip with a clothespin. Corn earworms are the most common of sweet corn pests. Their larvae are found feeding on the tips of sweet corn. You can handpick them, treat the tips with vegetable oil or a Bt pesticide or simply breaking off the tips.
* The minute trichogramma wasp is an important parasite that helps to control the earworm.
Whitefly - these tiny sucking insects with powdery wings can cause lots of damage, mainly inside and in the greenhouse. Use insecticidal soap. You can also use yellow sticky traps or pyrethrin as a last resort. Parasitic wasps help and nasturtiums will repel them. By the way, whiteflies suffer from an identity crisis as they aren't flies at all. Bioneem works on whitefly's.
Aphid - wash plants with a strong spray of water and soap. This method is called syringing and it often knocks down the colony enough so that beneficial insects finish them off. When possible, cover with floating row covers. The problem with row covers in this instance is that you can trap them in. (Aphids are soft bodies insects that come in numerous colors and are masters of reproduction. They're great at transferring diseases.)
Spider Mite - They are considered a nuisance on indoor and outdoor plants like tomatoes. Spider mites congregate on the underside of leaves and sip on plant juice. Signs are webbing and white or yellow specks in leaves and defoliation. They are hard to see as they are so small. You can check these buggers out by holding a piece of white paper and shaking the leaf over the paper. Observe the paper with a magnifying glass. The mites move slowly and have 8 legs in red, yellow, brown or green. Go online for pictures.
You can dislodge them with a spray nozzle on a hose and direct a high-pressure stream on the underside of leaves. Remove infested leaves and spray other leaves with Rosemary essential oils.
You can also spray a soapy solution on plant leaves. Reapply when needed. There are predator mites that prey on spider mites as well. A mixture of canola oil and dish detergent may also be effective on vegetable plants.
Thrips - There are more than 6,000 known species of thrips in the world. They are a common pest in greenhouses as well as ornamental and vegetable gardens. Thrips damage plants by sucking their juices and scraping at fruits, flowers and leaves. Leaves may turn pale, splotchy and silvery, then die. Host plants include onions, beans, carrots, squash and garden vegetables as well as flowers, especially, gladioli and roses.
The first thing to know about thrips is that the word is never singularized. "Thrips: can refer to a single insect or to many of them. Although they're tiny, their large numbers guarantee a large amount of destruction for plants. Cultivators of large number of ornamental flowers are at risk plus thrips are great at the transmission of viruses. On the other hand, the carnage of thrips is largely aesthetic; they rarely kill the host.
The best way to deal with them is through Integrated Pest Management or IPM. Its four key tenets are: maintenance of sanitary conditions, early monitoring for pest detection, biological controls, and at the last resort, minimal use of pesticides.
Greenhouses use IPM to cultivate beneficial fungi or nematodes (small round worms) to control pests' soil-bound eggs, "banker" plants to draw away pests from valuable crops.
Margaret Skinner, the entomologist for the University of Vermont (UVM), says that the marigold lures thrips away from valuable plants. It acts as a sacrificial plant. Skinner is not sure why, but believes it could be because marigolds flowers have ruffles in them and the thrips like to hide in them. Or it could be the aroma. Skinner's research has found that lacing topsoil with certain fungi is an effective way to destroy thrips' eggs. The thrips become infected when they drop down to the soil.Source on Thrips: Growing Pains by Ethan De Seife. Seven Days 6-25-14
IPM was developed in California in the 1970s. Lori King is the head grower at Claussen's Greenhouse in Colchester, Vermont. She taken IPM classes at UVM and has reduced pesticide use by 90 percent. She uses many biological controls including dunking plant plugs in a solution that contains beneficial nematodes as well as two fungal agents, RootShield and BotaniGard. She said that she can now control thrips plus spider mites.
You can control thrips by cleaning your garden of weeds and grass. If found, hose off plants with a strong stream of water. Release commercially available beneficial insects, such as pirate bugs, thrips predators, ladybugs and lacewings, to attack and destroy all stages of thrips infestations. There are also - Sticky Thrips Leafminer traps. You can also use neem, insecticidal soap, pyrethrum and spinosad for heavily infected areas. Pyrethrum is worse compared to spinosad as it harms beneficial insects, but it works quickly. However, spinosad also kills some beneficial insects. So be careful how much you use.
Leafminer - They are popular in greenhouses, home gardens and landscaped areas. Leafminers are the larval (maggot) stage of many insects. I get them on my spinach and beet greens in early summer. They feed on the upper and lower surfaces of leaves by tunneling.
What I do first is to pick off the infected leaves and make sure to continue to water the plants for healthy growth. I've used yellow sticky traps to catch the egg laying adults. Bio neem oil will break the pests' life-cycle by preventing larvae from reaching maturity. Neem is also a healthy organic alternative to some other broad-spectrum organic sprays like pyrethrin, which can kill bees. There is a leafminer parasite called Diglyphus isaea or you can use pyrethrin for a measure of last resort though I would not use it. During most years, I find I lose some spinach and beet greens but not too much.
Life Cycle of Beetles - (egg-larvae-pupa-adult)
Beetle Notes: The Chinese Southern Giant Mustard is a good trap plant for flea beetles. Bioneem, rotenone, pyrethrin and insecticidal soap also work on flea beetles. Pyola is a natural insecticide product that combines canola oil with pyrethrum. It's recommended for flea beetles, cucumber beetles, Mexican bean beetles, squash bugs, aphids, mites, and the Colorado potato beetle. However, a lot of the canola is derived from genetically derived canola oil.
Spinosad works on many beetles. Bioneem also works on beetles especially the Mexican Bean Beetle. Try first using floating row covers on beans. You can also use Bt (bacillus thuringiensis) on some beetles. There are many strains of Bt. For example, Bt San Diego is used on Colorado potato larvae of the beetle.
Flea Beetles - These are one of my top five pests. These leaf eaters (small bites) are one of most difficult-to-manage pests of eggplants and cole crops. These small dark beetles jump when disturbed. They are attracted to eggplants and mustard oils in the brassica family (cole crops), including mustards, radish, chinese greens, broccoli, cauliflower, kale and other plants with mustard oils.
You can start to treat a flea beetle infestation by using yellow and white sticky traps, even though it may not be enough to control the beetles. These traps will also give you an indication if you need to use a more radical solution. It you notice there are more than 5 beetles per plant, you need to take some action.
Banker Plants - You can use a trap crop like Chinese `Southern Giant", which will attract lots of beetles and keep some of them away from cole crops. You may need to plant more than one crop in the spring. These are called, "Banker" plants. I cover my plants with floating row covers. The row covers must be sealed tight. If these don't work, I use kaolin clay or spinosad (Entrust). This is my favorite control. Some years, I have planted my cole crops later - from mid to late June - when the cycle of the flea beetle begins to wind down.
Other Controls - Also, a rotenone-pyrethrum pesticide works, but use it sparingly as it kills some beneficial insects. Insecticidal soap provides partial control. Sprays combining rotenone and insecticidal soap are effective. Catnip may repel the beetles and a native braconid wasp also kills the beetles.
Japanese Beetles - There is hardly a gardener who hasn't encountered a Japanese beetle. These shiny, metallic blue-green beetles with bronze wings are deadly. They love to skeletonize leaves - eventually defoliating the plant.
These buggers are uncanny. The first beetles to emerge start to look for suitable plants to eat and start feeding immediately. They also send out an odor known as a congregation pheromone to signal late-coming/emerging beetles where to go. Mating starts soon after. The females feed on plants for a couple of days and then burrow into the soil to lay eggs. Shortly after, they will return to feeding and mating and start the cycle all over again. By the end of the season, each female will have laid 50 eggs.
Japanese beetles love roses, grapes, raspberries and some vegetables, especially beans. The larvae are white grubs that feed on organic matter and roots of grasses in the soil where they can cause a lot of damage. Pick off or knock the beetles into a bucket of soapy water. I know an old lady in Craftsbury, Vermont who does just that. She goes around with a bucket of soap and water in her garden and brushes the beetles into the pail every morning. Simple is as simple does.
Many folks can't be bothered to invest in beetle bag traps as they attract beetles to your yard. You can use beneficial nematodes (small round worms), which prey on the grubs. Apply them to the soil in late August and make sure the nematode product is fresh and soil is kept moist after it is applied. David Skelter, an extension entomologist at Ohio State University recommends beneficial nematodes over milky spore disease products, which are often used to control grubs in lawns. In Vermont, the summers are too short for milky spore to become established according to entomologists. If you have the will to will, you can let your lawn go dormant for the summer as the white grubs love a damp lawn. The "Chuckster" just chuckled at the thought of folks not mowing their lawns.
Other alternatives include spraying Japanese beetles directly with insecticidal soap, and or bioneem. Cover garden vegetables with floating row covers when the beetles first appear and spray with kaolin clay (sold as Surround). You can also hand pick the beetles every day by hand like the lady from Craftsbury, Vermont. Or you can use a Japanese Beetle Catch-Can yellow trap with bait. The floral and pheromone lure attracts male and female beetles. Keep the traps off to one corner of the garden. Once attracted by the scent, the beetles fly into the large yellow panels and are stunned on impact. They fall into the attached bag and can't fly out. Of course, you may attract all the beetles in the neighborhood and they may spread to your roses and other plants. So beware. Gardener's Supply sells one of the better traps.
Squash Vine Borer - Squash vine borer is among a trio of serious cucurbit pests. You can use floating row covers and pheromone-baited traps. When I see a green vine begin to wilt, I'll take a knife and remove the borer from the stem. Sometimes, they are hard to find.
European Corn Borer - these can be controlled through the release of trichogramma parasitic wasps that attack the egg stage, or with foliar sprays of Bt or spinosad.
Cutworm - use cutworm collars on transplants, delay planting, hand pick cutworms below soil surface
Root Maggot - apply floating row covers and set out transplants later in season - seems often in the soil with cabbages
Wire Worm - delay planting of tubers until soil warms up and use beneficial parasitic nematodes such as Grub-Away Nematodes. Use raw potato or carrot pieces as bait. Use crop rotations. To destroy larvae, cultivate the soil in the fall and spring.
Ants and Fire Ants - use diatomaceous earth on ants, aphids, beetle grubs and squash bugs. Spinosad works on fire ants. (Diatomaceous earth is a naturally occurring soft, siliceous rock that is easily crumbled into a fine white to off-white powder. It consists of fossilized remains of diatoms, a type of hard-shelled algae.)
Earwig - they are both beneficial and can be a garden pest. They are beneficial in that they eat aphids, mites and harmful nematodes. However, they also eat ornamental and vegetable plants. Use diatomaceous earth around beds and base of plants to control them. The earwig's only insect predator is the tachinid fly. This fly is attracted to alyssum, calendula, dill, and fennel.
Nematode - these microscopic worms feed on the roots of plants. The symptoms of their work is comparable to nutrient and water deficiency resulting in yield loss, stunting and wilting. The best way to deal with them is to use predatory nematodes, solarization, sanitation methods and crop rotations. Some plants are more resistant and tolerant than others to the harmful nematodes.
Slugs and Snails - Because slugs and snails are soft bodied creatures, making a perimeter of oyster shells, eggshells, sharp sand by sprinkling around plants, will deter them. For container plants, make a ridge around the top with copper flashing. You can purchase these thin copper ridges at garden centers. Because slugs and snails are so full of water, the copper will give them an electric shock causing them to slowly head south.
One traditional method mentioned earlier are beer traps - either homemade (pie plates) or the plastic commercial types, which are placed very close under the plants. The commercial ones have tops which are removed in the morning with the kill. I've used boards for years along with homemade beer traps. Just lift the boards and you'll find lots of slugs. Organic iron phosphate pellets work by sprinkling around the plants. They are toxic to slugs and snails but not the children, birds and pets. You need to re-apply the pellets after it rains.
Tarnished Plant Bug - It's best to keep garden clean, use floating row covers and spray with gnome.
Squash Bug - You find them on melons, squash, cucumbers. It's best to squish the bugs and if they get to be too much, use spinosad or the repellant, kaolin clay is pretty effective. Mulching with newspapers and hay, combined with tight floating row covers is also effective. Use crop rotations and fall sanitation methods as well.
Stink Bug - I use the same method as with squash bugs.
Leek Moth or (onion leafminer) - targets plants in the allium family - onion, garlic, leeks, chives and shallots. Early warning signs are brownish white patches on leaves, followed by larvae and eggs found on the plant, and pinholes found closer to the center of the plant. Products like Captain Jack's Dead Bug, whose key operative ingredient is spinosad. Natural predators are frogs and beetles.
Swede Midge - appear to feed only on plants in the brassica (cabbage and mustard family) the adult is a light brown fly eggs to larvae ( small maggots ) works on growing tips of plant puckered and crinkled leaves which feed on the plant tissue of the brassicas.
The Bug Blaster - This new type of spray nozzle hits the plant from many different angles and washes off the bugs. It's called the "bug blaster" and should fit on any watering want or garden hose. In some cases, you need to use it a number of times. It's sold by Custom Hydroponic. Let me know how it works for you.
Gardens Alive sells a product called, Garden Pest Bait, which kills cutworms, slugs, snails, earwigs, sowbugs, pill bugs, crickets and ants. It comes in granular form and is easy to spread, sort-of clean to handle, economical and effective for up to four weeks. It can be used around vegetables, fruit trees, berries, ornamentals, shrubs, flowers, trees, and lawns. It's made up of spinosad and iron phosphate.
You should rinse your eyes and skin after using if it spreads on you in the air. It may cause irritation. Even though it's an organic product, one must still be careful. There are many products like Garden Pest Bait, such as Bull's Eye, whose main ingredient is spinosad.
Vern Grubbinger, the Vegetable and Berry Specialist at the University of Vermont Extension says that garden diseases are like a kitchen stool. To stand on their own, (to have an infection), they need three legs: a susceptible host (for example, a tomato, the presence of an infectious agent, like a fungus, and the right environmental conditions - lots of rain and sometimes, depending on the fungus, high humidity and wind to move the fungus around.
Grubinger says it's best not to "host the party" by growing resistant and tolerant plants to disease. This will help. He goes on to say to "lock the doors" by disposing of diseases plants and seeds that have been infected and to "stop`em in their tracks" by using wide rows with good air flow and well-drained sites where diseases can't spread as much.
Since vegetable gardening is the number one hobby in the United States, keeping a garden healthy requires lots of attention. Most garden diseases are caused by fungi - microscopic relatives of the common garden mushroom. Mature fungi release millions of spores carried by the wind onto plants.
And if conditions are ideal with lots of moisture or in many cases high humidity, the spores will germinate and penetrate the tissues of leaves. A lot of fungi over winter on dead leaves on the soil so the spores from these leaves splash up to lower leaves and make their way up the plant as the season progresses.
Here are ways to deal with fungal diseases:
Fungi aren't the only plant diseases. Some diseases, such as fire blight are caused by bacteria, while others (like tobacco mosaic) come from viruses. These are not easy to control in the home garden.
Some diseases include: fusarium wilt, powdery mildew, mosaic virus, corn blight, smut, scab, bacterial wilt, downy mildew and late blight in tomatoes and potatoes.
Suzanne DeJohn - National Gardening Association
Vern Grubinger - University of Vermont Extension Service
The most serious disease to hit Vermont in the last few years is the late blight in tomatoes and potatoes. There was a confirmed case in late July of late blight on tomatoes in Huntington. Although the disease can infect tomatillos, eggplants, peppers, and other members of the potato family, it has only been found on tomatoes and potatoes in recent years.
Late blight spores are easily carried long distances on the wind. Once the plants are infected, they need to be destroyed. The symptoms start as nickel-sized, water-soaked spots on tomato and potato leaves. Unlike other fungal blights, the spots do not start at the bottom of the plant. Under moist conditions, whitish grey fungal growth can be seen on the leaf undersides. If the weather is wet or there are morning fogs or lots of dew, the disease can spread rapidly in a matter of days. (Go online for pictures.)
Stems and fruits can also be infected with tomatoes forming large brown areas. The unaffected fruit can be eaten. Place infected fruit and leaves and stems in a garbage bag and take to the dump.
Do not compost the plants.
If the potato vines become infected, cut the tops and place in plastic bags. Wait 2-3 weeks and dig up the tubers. Organic growers can use a copper fungicide if found early enough. Fungicides will only protect healthy tissue. Repeat applications.
Ann Hazelrigg - Plant Diagnostic Center, University of Vermont.
* You can go to www.uvm.edu/mastergardener for instructions on how to submit samples of diseased plants.
Additional information can be found at: www.hort.cornell.edu/lateblight.
Serenade - It's used for fungal and bacterial diseases. This biofungicide controls foliar diseases like leaf blight, black mold, early and late blight, powdery mildew, and other diseases. It contains Bacillus subtilis. Serenade works on all fruits, vegetables and ornamentals and is safe - so safe it can be applied the day of harvest. Repeat every seven days. Don't water plants within four hours of application.
Sulphur - Sulphur is often used as a fungicide in apple orchards and in planting potatoes.
Bordeau Mixture - This is a copper based mixture which has been used for years to combat fungus.
Organically approved bicarbonate fungicides have recently become available. They seem to work well against powdery mildew. Peroxide-type materials are also in use to suppress diseases on plant-surfaces. Other organic options for disease suppression contain microbes or their by-products, including species of Trichoderma, Bacillus, and other beneficial organisms.
Equisetum (horsetail) - This ancient plant is used to deal with fungal diseases. You cook up a large pot full of horsetail and water let it cool and then the solution spray on plants. It is nontoxic to bees and beneficial insects, and, unlike sulphur, it's non-irritating to lungs and skin. Horsetail is one of the Biodynamic herbal preparations.
* Ann Hazelrigg of the University of Vermont's Plant Diagnostic Center, was most helpful with the material on insects and diseases.
The following information was taken from the Entomology Research Laboratory at the University of Vermont (UVM). This work came about because of the need to control pests and diseases in a more ecological way in greenhouse settings. Their method of control is called Integrated Pest Management (IPM).
"IPM is a way to manage insect pests and diseases on crops by combining several complimentary strategies such as sanitation, pest detection and biological control. `Soft chemical pesticides may be use, but only when necessary." The project is working to promote the greater adoption of essential IPM practices for greenhouse growers throughout Maine, New Hampshire and Vermont by providing technical assistance and hands-on IPM education and workshops.
Colleen Armstrong manages the greenhouse work at UVM along with Margaret Skinner, an insect expert. (802) 656-5440
For more comprehensive information and pictures of pests and their enemies go to the UVM Extension website - Greenhouse Pests and Biological Controls. Ongoing research and workshops are held throughout Vermont for greenhouse growers and farmers. The newest publication is called: "Greenhouse Manager's Guide to Integrated Pest Management in Northern New England".
More and more gardeners and farmers are using greenhouses to grow food crops in Vermont. Some are heated and others are non-heated.
Pests: The key pests are aphids, thrips, white flies, mites, mealy bugs, scale, shorefly. spider mite, mealy bugs and fungus knats.
Natural Enemies: Natural enemies of these pests are also shown in the website including: wasps which parasitize aphids and whiteflies, the larvae of gall midge are aphid predators, adults and larvae of the ladybeetle attack eggs and nymths of greenhouse and silverleaf whiteflies and aphids. Mites are not incects, but are closely related to spiders. They attack common pests in greenhouses like mites. There are a number of different mites, wasps, midges, and lady beetles.
Some of the free biological controls come from Convergent Lay Beetles, Syrphid Flies, and Green Lacewing Eggs.
The first thing gardeners need to do is identify the insect pests, their life cycles and how their mouthparts do damage to the plants. Yellow sticky traps come in handy in this regards.
Gardeners need to know the specific biocontrols for these insects. Many biocontrols are successful by managing certain stages of the insect's life cycle at certain stages of their own life cycle. Identifying what insect damage looks like on plants is essential for knowing whether a pest infestation is increasing. Also, knowing which crops you're growing are susceptible to certain pests and diseases is also a key component for successful pest management.
There are so many outdoor pest controls that it's hard to keep up with all the new products. Over the years, I haven't had to use many of them, even though they come in handy when needed. Here is a short list: Summer-weight garden fabric (floating row covers), plant protection tents made from garden fabric, bird netting, garlic clips for deer, deer repellent and deer fences, Serenade garden disease control for foliar diseases like blights, copper slug tape and slug guard, Japanese beetle catch-can with bait, milky spore powder (doesn't work in Vermont as it is too far north), and Japanese beetle killer, beneficial bugs, Gnome oil concentrate, grub garb, actinovate fungicide, copper fungicide gopher and mole repellent, diatomaceous earth, Serenade, and the list goes on and on.
Organic Pest and Disease Controls include: Beneficial Insects, Beneficial Plants, Companion Planting, Barriers and Traps, Sprays, Homemade Remedies, and Common Insects and Controls.
When blooming, the following plants attract beneficial insects with their nectar and pollen: Parsley family - parsley, fennel, coriander, dill and chervil, Sunflower family - (sunflowers, daisies, asters and cosmos), Sweet allysum and buckwheat.
Companion planting helps to deter harmful insects with the use of flowers, herbs and vegetables. Some plants like each other and other don't, just like our relationships with people. You can design your garden in such a way that plants with natural defenses for pests are planted adjacent to plants that are more susceptible.
Marigolds secrete substances from their roots that kill harmful nematodes, marijuana deters the white cabbage butterfly with its odor, and leeks deter the carrot fly with their smell and leeks grow well with celery. Kohlrabi does not do well near pole beans, but grows well with beets and onions. Onion rows alternating with carrot rows serve the double purpose of repelling both the onion fly and carrot fly. I've been growing beans and potatoes in adjacent rows for year and have found fewer potato beetles. It could be that the nitrogen-fixing bacteria in the root nodules of the beans helps the potatoes to grow stronger. A small amount of horseradish, one plant in the corner of a potato patch, aids the general health of the potatoes. Potatoes and sunflowers stunt each other. Interspersing flowers and vegetables can also encourage pollinators like bees and butterflies to visit your garden.
Source: The classic book on Companion Planting is called Companion Plants by Philbrick and Gregg. Most of the above information comes from this book. Dr. Rudolf Steiner, the founder of Biodynamics, brought the concept of Companion Planting to a group of farmers in East Germany in 1924. There is a part of a chapter on Companion Planting in The Woodchuck's Guide to Gardening called, Let the Force Be With You.
Traps can attract insects using color, taste, and sex hormones. For example, yellow sticky traps will lure aphids, whiteflies, thrips and leaf miners.
Sticky Traps - These traps are made of a particular color that's coated with a sticky substance, like tangle trap, and are used to catch insects that are attracted to a particular color. For cucumber beetles, you can use a rigid material painted in white with tangle trap. Flea beetles are also attracted to white traps as are whiteflies. The beetles will be attracted to and will stick onto the trap. Yellow traps attract whiteflies, fruit flies, flower thrips, fruit flies, leafhoppers, midges, leafminers, and winged aphids. Light blue traps attract flower thrips, and red spheres attract the flies whose eggs hatch into apple maggots. You can make your own sticky traps (go online) or purchase them at a garden center or from a catalog.
Pheromone Traps - Insects produce powerful smells called pheromones that are used to lure the opposite sex. Scientists have duplicated some of these scents and used them to bait special traps for luring the targeted insect. Because these traps attract mostly males, they aren't that effective. However, they are useful as an early warning sign when particular pest moves into your garden or orchard. Before you use the traps, use floating row covers. Once you find the pests in the traps, it's time to apply two organic pesticides, Bacillus thuringiensis and Surround. Pheromone traps can be used to catch moths that produce armyworms, cabbage loopers, corn earworms, European corn borers, and cutworms.
Cutworm collars make an effective physical barrier to prevent the cutworms from girdling plants like tomatoes, broccoli and peppers. Simply cut out a one-and-a-half inch strip of cardboard and place a collar around the plant.
Floating row covers (remay) are translucent, white, porous polyester fabric that acts as insect barrier, while letting in 80 percent of available light. They keep flying insects from laying eggs on the plants. When pollination begins to take place (when cucumbers begin to flower and bees do their work), it's necessary to remove the row covers. The bees can't pollinate with covers over plants. There are lightweight and heavier weight row covers. The heavier weight covers also trap some warmth. Row covers are especially helpful for cucumbers beetles, cabbage moths, Colorado potato beetles, most aphids, Mexican bean beetles, flea beetles, squash bugs and tomato hornworms.
* See The Woodchuck's Guide to Gardening for more information on floating row covers (Remay).
Many homemade sprays combine garlic, onion, hot peppers and water. Go online for recipes. Insecticidal soap is a liquid commercial product that dissolves the skins of insects like mites, aphids, whiteflies and other soft-bodied insects. It should only be sprayed on plants with pests. Don't spray on hot days and rinse the soap off the plants after a few hours. Please follow the directions on the bottle.
Oilsprays (oil sprays) work by suffocating pests. To be effective the oil spray must hit the pest directly. Use "dormant" oil sprays to kill insect pest eggs and disease spores on the bare branches of trees and shrubs during the dormant (winter) season. Limit sprays to where you can see the pests. Don't spray during peak flowering times and blossoming. Spray early in the morning before bees become active.
Rotenone and Pyrethrum are botanical insecticides (poisons) derived from plants that can effective against adult beetles and leaf miners. Rotenone needs to be handled carefully and be used sparingly. (It is mildly toxic to humans and other mammals, but extremely toxic to insects and aquatic life, including fish. Studies with rats and the injection of rotenone has shown a development of symptoms similar to Parkinson's disease.)
Bio-gnome, derived from the seeds of the Gnome tree can be used to interrupt the life cycle of the Mexican Bean Beetle larvae and other beetles. Gnome trees are fast growing shade trees as well. I planted young gnome trees in Nicaragua in 1987 for the purpose of shade.
Bacillus thuringiensis (Bt) is a naturally occurring, soil-borne bacteria that is effective in controlling specific insects in their larvae stage. There are different Bt's for different insect pests, like cabbage and corn earworms. The larvae stage in an insect's life cycle is the stage during which most of the feeding takes place.
There are Bt controls for potato and cabbage larvae. Don't spray indiscriminately. For example, the type of Bt that kills cabbage loopers can also kill the caterpillars of the beautiful butterflies you love. Only spray when you have a pest problem. Don't spray in the heat of the day. You will need to repeat spraying after a few days if you continue to see the larvae. The most common strain of Bt kills caterpillars, like cabbage loopers, tomato hornworms, cabbageworms, corn earworms, European corn borers, and squash vine borers. Spraying when the larvae are small is more effective. Another Bt kills the larvae of the Colorado potato beetle.
The Colorado Potato Beetle is controlled initially by the hand removal of beetles, eggs, and larvae. For many gardeners who grow a small patch of spuds, this works just fine. If the buggers get out of control, you may need to use Bt or spinosad, which is used on many beetle larvae. (See below for a description of spinosad.)
Parasitic Nematodes - Once parasitic nematodes are inside a pest, they release a bacterium that kills the insect host within a day or two. Although good nematodes occur naturally in the soil, there usually aren't enough of them to control pests in the garden. You can purchase them as a safe, organic, and nontoxic form of pest control. Parasitic nematodes attack armyworms, corn earworms, squash vine borers, soil-dwelling grubs including Japanese beetle larvae, flea beetles, root maggots, and cutworms.
Spinosad - an organic insecticide that works against caterpillars and other leaf-eating insects. It is relatively new microbial insecticide that is derived from a species of Actinomycetes bacteria. It's fermented product. Spinosad is replacing the well-known organic biological insecticide Bt (Bacillus thuringiensis. This newer organic insecticide controls caterpillars as well as leaf miners, thrips, Colorado potato beetle larvae, cabbage looper, imported cabbage worms, earworms, and even fire ants.
The spinosad bacterium was discovered in 1982 in an old Caribbean rum still. It was found that these bacteria produce a substance that works as a neurotoxin in many insects. Susceptible insect species that are exposed to spinosad become excited to the point of exhaustion, stop eating and die. Spinosad breaks down in sunlight, so late-day applications work best. It lasts longer than Bt.
"Generally, spinosad works best against insect larvae. It's also called Entrust and Monteray Garden Insect Spray. Spinosad is also used to control fleas on dogs and lice in humans. It can kill bees and other beneficial insects so use sparingly." Source: Mother Earth News June/July 2011
* Caterpillars are the larval form of members of the order Lepidoptera - the insect order comprising butterflies and moths. They are eating machines.
Kaolin clay is made up of a fine white clay used for the manufacture of porcelain and bone china. It works in the garden by reducing egg-laying activity and feeding. Its brand name is Surround. When applied to fruit crops and vegetable plants, it forms a white film and suppresses a wide range of pests, especially those that damage fruit crops like pears, apples, grapes, berries, and some vegetables. Surround forms a barrier film by creating a hostile environment for insects and mites and works as an anti-feedant. The particles in the clay adhere to the insects acting as a strong irritant. Surround needs more than one application to be effective. One of the concerns with Surround is that it will block the sun and kill fruit trees if used over a long period of time.
UVM Extension Master Gardener Helpline
UVM Plant Diagnostic Clinic
National Gardening Association (NGA) Williston, Vermont. You can see great pictures of these insects on the NGA website. They explain where the disease is on the plant and remedies.
Charlie Nardozzi, Author of Northeast Fruit & Vegetable Gardening.
The Woodchucks Guide to Gardening (My first book)
An informative book on organic controls in the garden is one of the Rodale books entitled, The Organic Gardening Book of Natural Insect and Disease Control by Fern Marshall Bradley, Barbara Ellis, Deborah L. Martin.
You can also use the handy guide in the Gardens Alive Catalog called Your Common Guide to Insect Pests and How to Control Them.
Or contact Johnny's Seeds and Fedco in Maine, my two favorite seed catalog companies.