This is a selective bacterial disease, highly effective against caterpillars and the larvae of moths. During spore production, Bacillus thuringiensis produces crystals that act as a stomach poison on the insects eating the treated plants. This substance is not toxic to plants, man, or other animals, and can be applied even up to the day of harvest.
BT controls the fruit tree leaf roller, as well as tent caterpillars — the disease attacking the pest in the caterpillar stage after they have come out of the tent. The disease is widely used to protect commercial crops of celery, lettuce, cabbage, broccoli, cauliflower, mustard, kale, collards, and turnip greens. It is also effective against the tobacco budworm and the bollworm.
Special strains of BT have been developed to kill other pests such as mosquito larvae and Colorado potato beetles. BT products are widely available, under various brand names, from garden centers and mail-order catalogs.
Bush beans planted with potatoes protect them against the Colorado potato beetle. In return, the potatoes protect the bush beans from the Mexican bean beetle. It is considered best to plant the beans and potatoes in alternate rows.
Birds around the garden are generally recognized as one of the best controls against insect pests. Particularly useful are the purple martins, which must catch flying insects almost constantly in order to live. Well-made martin houses set up away from large trees will attract martin colonies. Feeders and bird waterers will also encourage other birds to visit and nest near your garden.
Birds are particularly attracted to hackberry, chokecherry, elderberry, Tartarian honeysuckle, mulberry, dogwood, Japanese barberry, red and black raspberries, viburnum, Hansen’s bush cherry, Russian olive, hawthorn, and sunflowers. Evergreen trees and thornbushes are attractive for nest-building. Certain forms of cactus are attractive for this purpose in the Southwest.
The purple martins rid orchards and garden areas of incalculable numbers of injurious insects, devouring them in the winged stage.
Birds, however, can be too much of a good thing at times and may become very destructive to the food plants we grow for ourselves. From the Chinese we have this suggestion: When fruits start to ripen, hang sliced onions in the trees — the birds dislike the scent and will avoid the fruit. Hanging empty milk cartons in fruit trees from a string so they twirl in the breeze will deter many birds. Change their position occasionally, and perhaps also use bright, fluttering ribbons or strips of cloth.
If crows are a problem for a corn or watermelon patch, put up several stakes and string white twine around the patch, crisscrossing it through the center. To the birds this will look like a trap and they will avoid the patch.
This insect is particularly detrimental to broad beans, and it is advisable to use a fermented extract of nettle to keep it under control. Its natural enemy, the lady beetle, will help. Intercropping with garlic, or placing an occasional plant of nasturtium, spear-mint, or southernwood in the rows of beans, also is a good plan.
Nasturtiums planted around fruit trees repel borers, while garlic and other alliums such as onions and chives also are good.
Experiments have shown that castor beans planted around a garden will repel moles, and they also are good to repel mosquitoes.
This is an agricultural crop in some areas where it is grown for the oil in the seed, yet all parts of the plants are poisonous to livestock and humans, particularly the seed. Two or three seeds eaten by a child can be fatal and as few as six can cause the death of an adult. The beans also carry an allergen that causes severe reactions in some people when handling castor pomace. This danger can be eliminated if the seed heads are clipped off or destroyed before they mature.
To form an effective mole repellent, plant castor beans every five or six feet around the perimeter of the garden. Use them also as a companion crop: Plant several pole beans close to their bases and let them climb the tall-growing plants. The largest variety of castor bean, zansibarensis, grows eight feet tall, and has large leaves and beautiful variegated seeds of various colors. Sanguineus grows seven feet tall and ‘Bronze King’ five feet.
Extracts of chinaberry have been found useful against cockroaches and termites. The little-known cockroach plant (Haplophyton cimicidum) from Mexico also is valuable in controlling this pest.
A three-inch cardboard collar around young plants extended one inch into the ground and two inches above will foil cutworms. Use cardboard cut from toilet paper or paper towel rolls, or cut off the top and bottom from a quart-size milk carton and cut the remainder into three collars.
A used matchstick, toothpick, small twig, or nail set against the plant stem will keep the cutworm from wrapping itself around the plant and cutting it. Oak leaf mulch will repel cutworms, too.
This effective remedy against many insects is made from the finely ground skeletons of small, fossilized, one-celled creatures called diatoms, which existed in the oceans and constructed tiny shells about themselves out of the silica they extracted from the waters. The microscopic shells, deposited on the floor of the ancient seas, collected into deposits sometimes thousands of feet deep.
This earth contains microscopic needles of silica, which do their work by puncturing the bodies of insects, allowing vital moisture to escape from them. The insects die from dehydration. This earth is so finely milled that it poses no threat to either humans or animals, but these particles, when taken internally by insects, interfere with breathing, digestion, and reproductive processes.
Diatomaceous earth will not harm earthworms, which are structurally different from the insects. The earthworm’s outside mucus protection, coupled with its unique digestive system, enables it to move through soil treated with diatomaceous earth without harm.
Many gardeners use diatomaceous earth as a dusting agent to give effective control against gypsy moths, codling moths, pink boll weevils, lygus bugs, twig borers, thrips, mites, earwigs, cockroaches, slugs, adult mosquitoes, snails, nematodes, all species of flies, corn worms, tomato hornworms, mildew, and so on. For field crops and in orchards, the diatomite particles are best applied with an electrostatic charger, which gives the particles a negative charge, causing them to stick to plant surfaces.
Eelworms or nematodes are tiny, sightless, eel-shaped organisms that pierce the roots of plants to feed or to lay their eggs inside, causing knots to form. When organic matter is incorporated into the soil, it encourages beneficial fungi and other nematodes that feed on the plant-parasitic variety of eelworms. These beneficial fungi grow in decomposing vegetable matter and kill the nematodes. It is possible to reduce wireworm and nematode attack, too, by placing a heavy dressing of barnyard manure on grassland before plowing.
These microscopic nuisances are discouraged by marigolds, scarlet sage (Salvia), or dahlias (Dahlia). Asparagus is a natural nematocide. Tomatoes grown near asparagus thus are protected, while in turn the tomatoes protect the asparagus from the asparagus beetle.
Flying insects such as flea beetles are known to dislike moisture. Very often they can be discouraged by watering the garden in full sunlight. I find them annoying but not particularly destructive to eggplant, tomato, turnip, and radish plants. The damage is mostly cosmetic, and strong plants quickly grow out of it, the plant becoming less attractive to the beetles as the leaves enlarge and toughen a little. Light cultivation and the addition of organic matter to the soil both discourage the beetles and help the plants.
Bruised elderberry leaves laid over the rows of plants are a deterrent to the beetles, and they also are repelled by mint and wormwood. Beetles attracted to radish or kohlrabi may be controlled by interplantings of lettuce.
Greenhouse gardeners, who frequently have difficulty controlling aphids, ants, and termites as well as that all-time pest, whitefly, find smoke from oak leaves effective. The leaves are not poisonous, do not kill soil bacteria, and leave no harmful residue. Smoke the leaves for about a half hour, keeping the greenhouse door tightly closed.
See the Herbs chapter.
These burrowing rodents may be repelled by plantings of scilla bulbs. The scillas, sometimes called squills, are flowering, bulblike ornamentals that have grasslike leaves and clusters of flowers at the top of long stems. They are easy to grow, and bloom in the early spring. They may be grown among vegetables as well as in flower beds. But be cautious — the bulbs should never be eaten.
Grasshoppers are very difficult to control, especially where they come in from surrounding fields, but this spray will help: Grind together two to four hot peppers, one mild green pepper, and one small onion, and add to one quart water. Let stand 24 hours and strain. This mixture also is good against aphids.
During times of grasshopper infestation, an after-harvest plowing will discourage egg-laying, while spring tilling before seeding will prevent grasshoppers from emerging from the eggs still present. Extracts of chinaberry have proved useful, while sabadilla dust or extract is effective against these and many other insects. (See Insecticides, Botanical in this chapter.)
Grasshoppers can be attracted by this bait: Fill several twoquart mason jars with a 10 percent molasses solution and place around the area where the infestation is the worst.
Chickens are of great value in an orchard, for they eat grasshoppers and other insects and at the same time add their manure to aid the fertility of the soil. The coop may be moved every few days to a new location.
Wild birds attracted to the garden eat a great many grasshoppers and surprisingly cats will kill and eat them, too. I think this is partly for the fun they get out of the chase.
Grasshoppers will eat almost anything except horehound, but grasshopper-resistant varieties of corn and wheat have been developed.
This wasp has been found by the Brownsville Experiment Station in Texas to parasitize at least 27 destructive species of moths and butterflies, but it prefers to deposit its eggs in bollworms and tobacco budworms.
Insects are largely attracted by scent and may be lured away from certain crops by other plants placed nearby. Plants such as nasturtium and mustard, both of which contain mustard oil, frequently are used for this purpose. These are called trap crops. Insects feed on and lay their eggs in trap crops, which should be destroyed before the eggs hatch.
Insect repellents may be prepared from crushed leaves, infusions, or essential oils of such botanicals as citronella, eucalyptus, pennyroyal, bergamot, cedarwood, clove, rose geranium, thyme, winter-green, lavender, cassia, anise, sassafras, bay laurel, and pine tar. Ginkgo, elder, pyrethrum, and lavender repel ticks or other insects. Other plants such as cedar, quassia, and teakwood themselves are immune to insects.
See also the Insect Control through Companion Planting chart, page 154, in this chapter.
Several plant derivatives are available commercially as insecticides. (See Sources.) These materials break down more quickly than man-made insecticides and (except for nicotine) are relatively nontoxic to humans when used as directed. They kill bees and other beneficial insects as well as pests, however, and can be toxic to other life-forms such as fish. As with any pest-control products, read the label and follow the directions exactly.
Pyrethrum is prepared from the flowers of Chrysanthemum cinerariafolium or C. roseum. It is used alone or in combination with other botanicals against a wide variety of pests, including aphids, leafhoppers, spider mites, harlequin bugs, and imported cabbageworms.
Rotenone comes from the roots of tropical plants and is a powerful stomach poison for chewing insects.
Nicotine. Tobacco and its main alkaloid, nicotine, have been used as an insecticide since the late seventeenth century. Nicotine, a contact poison, is toxic to mammals as well as insects and should be handled very carefully.
Ryania, from a Latin American shrub native to Trinidad, does not always kill insects outright but rather makes them ill, causing them to stop feeding.
Sabadilla. When heated or treated with an alkali, the seeds of this plant become toxic to many insects. Oddly enough, this quality increases with age during storage. The extract is effective against a large group of insects such as grasshoppers, corn borers, codling moths, webworms, aphids, cabbage loopers, and squash bugs. Be cautious in handling the dust and do not breathe it in.
Neem oil is made from the seeds of the neem tree, native to India. It is useful against Japanese beetles and the adults of many other chewing insects, acting as a repellent and as an appetite suppressant, and also stops the development of larvae.
Every garden has both “good” and “bad” bugs, yet from a gardener’s point of view only a few are relatively destructive. Some vegetables seem to have a natural, built-in resistance: carrots, beets, endive (including escarole and witloof chicory), chives, okra, Egyptian onions, parsley, peppers, and rhubarb. Under good growing conditions, lettuce might be added to this list, too.
Numerous vegetables and herbs listed in this book help other vegetables to resist insects when grown with or near them. Scientists have done a great deal of research, also, on why certain other plants are attractive to insects. They have come up with something that organic gardeners knew all along: Insects prefer to eat plants having high concentrations of free amino acids, such concentrations being enhanced if the plants are improperly nourished. Organically grown vegetables produced on balanced, healthy soils have significantly lower levels of free amino acids in their tissues than plants grown where chemical fertilizers have destroyed the balance. Such “organic” vegetables are less tasty to insects.
In addition, vegetable varieties have been bred for resistance to specific pests. Your county’s Cooperative Extension Service may have recommendations on good choices for local conditions.
Legumes planted in a rotation will protect grain crops and grasses from white grubs and corn rootworm. Chinch bug on corn and flea beetles are controlled by growing soybeans to shade the bases of the plants. The herbs in this chart may be planted as specific controls.
These famous eaters of aphids may be purchased for garden release. (See Sources.) The problem, especially in small gardens, is to keep them there. If there is a real need for their services and there is plenty of ladybug food around, they are more likely to stay.
The way you release them will make a difference. Do not strew them about like grains of corn but rather place them by handfuls — carefully — around the base of infested plants. Their natural instinct is to climb the nearest plant and start hunting for food. Do your “seeding” gently, since rough handling, especially in warm weather, may excite them to flight. Early morning or evening is the best time.
Lamb’s-quarters, which sometimes harbor the leaf miner, also may play host to the beneficial ladybug. Newly placed ladybugs are dependent on their hosts (which also may be Chinese celery, cabbage, or other plants), and they must find aphids in sufficient quantity to keep them in the vicinity and ensure reproduction. After one mating a female will produce from 200 to 1,000 offspring.
In the spring you can often find the eggs of ladybugs on the undersides of leaves, near their early food supply, aphids. You will see them standing on end in clusters of 5 to 50, generally yellow or orange in color. The alligator-shaped larvae are blueblack and orange-spotted.
Mice and rats are repelled by fresh or dried leaves and the oils of mints, by camphor, and by pitch pine. Mothballs repel rabbits as well as mice but should not be used where food crops are grown or where children can pick them up.
Sea onions, white lavender, wormwood, and spurge repel mice, while everlasting pea is useful against field mice, and leaves of dwarf elder protect against mice in granaries.
If mice like your garden too much, repel them with bulb plantings of daffodil, narcissus, scilla, or grape hyacinth.
Cows and goats give more and richer milk when fed on stinging nettle hay or members of the Umbelliferae family. We always saved discarded carrots and carrot tops when we kept milk goats, which also liked prunings from rosebushes if the thorns were not too prominent.
Skim milk may be used as a spray on tobacco and other plants subject to mosaic virus, and on peppers and tomatoes grown in the greenhouse. Pickers in commercial pepper and tomato plots find it useful to dip their hands in skim milk to avoid transmitting the mosaic virus, while whey proteins are effective, too.
A milk and blood spray has been used in orchards to control fungi, and a milk and coal tar mixture against chinch bug.
Sour milk or butttermilk may be sprinkled over cabbages against cabbageworms.
This widely used bacterial organism gives protection against the Japanese beetle by producing a fatal disease in the grub. Because it brings about an abnormal white coloring in the insect, it is called milky.
It was developed in 1933 when a field survey in central New Jersey discoverd a few abnormally white Japanese beetle grubs, which examination showed were teeming with bacterial spore.
This disease was studied by the Bureau of Entomology and Plant Quarantine, where attempts were made to culture it for release. Treatment with the milky spore on experimental plots showed a more than 90 percent mortality in two months. In areas where the disease had been established naturally, equally high kills were found. This disease, occurring naturally in Japan, has kept the beetle from becoming a serious problem there.
The spore ordinarily needs only one application and then continues and spreads itself. It can be applied to the soil at any time except on a windy day or when the ground is frozen, but it is best to treat mowed or cropped areas. Apply a teaspoonful of the spore disease powder on grass or sod spots three to four feet apart and in rows the same distance apart. The beetle grub feeding in the soil will then take in the bacteria spores.
When a healthy grub becomes infected, the spores give rise to slender vegetative rods, which multiply in the blood by repeated divisions. In a short time the normally translucent blood of the grub will become milky in appearance, and eventually the grub dies. The spores stored in the body cavity then are released in the soil and are taken up by other grubs that in turn become infected. As the cycle continues, the spores increase in number and, since more grubs are killed, fewer and fewer adult beetles emerge to feed on crops. The disease is cumulative and self-perpetuating.
Milky spore disease is sold under several trade names. (See Sources.)
Neem oil is being increasingly used as a Japanese beetle control with considerable success. (See Insecticides, Botanical in this chapter.)
Less effective but still useful methods of combating the Japanese beetle include companion plantings of geraniums among roses and grapes to drive the beetles away. Larkspur eaten by the beetles will kill them, while soybeans work as a trap crop. The beetles are rarely destructive to cabbage, carrots, cauliflower, eggplant, onions, lettuce, parsley, peas, potatoes, radishes, spinach, squash, sweet potatoes, tomatoes, and turnips.
This is one of nature’s very own insect traps. The covering of glandular hairs exudes a viscous oil capable of trapping small pests such as ticks. It does not kill them, but stops them from crawling upward to come in contact with an animal. Cattle pastured on this grass in Guatemala were found to be free of ticks within a year, and it has been planted in Florida with good results. At the same time it provides good forage for cattle, which like to graze on it. It also repels mosquitoes and the tsetse fly.
Moles generally are considered a nuisance, and they do consume beneficial creatures such as earthworms, but they also feed on Japanese beetle grubs. They are deterred by a few plants of caper spurge (Euphorbia lathyrus) strategically placed, by daffodil bulbs, and by castor bean plants. Thorny twigs of raspberry, rose, hawthorn, or mesquite pushed into burrows will scratch the moles and cause them to bleed to death.
Garlic-based oil (see Garlic in the Herbs chapter) is effective in killing mosquito larvae in ponds. Myristicin, a synthesized compound found in parsnips, also is effective as a selective insecticide against the larvae, as is Bacillus thuringiensis.
The leaves of molasses grass (Mellimus minutiflora) and sassafras are mosquito repellents, and I find that castor beans planted around my garden make it more pleasant to work there in the long, cool western twilights when I do most of my garden work.
Euell Gibbons says that American pennyroyal (Hedeoma pulegioides), sometimes called squaw mint and a native American plant not to be confused with the European pennyroyal (Mentha pulegium), is a natural insect repellent. A handful crushed and rubbed on the skin will not only emit a pleasant smell but also repel mosquitoes and gnats.
If moths and millers are troublesome in fruit trees, place one cup molasses in one and a half cups water and hang in small buckets or cans from the limbs. Remove the insects occasionally or make new solutions. This remedy is particularly helpful if used in peach trees.
See Eelworms in this chapter.
Used properly and at the right time, dormant oil sprays are effective, particularly in orchards, against many chewing and sucking insects. The oils make a tight film over insect eggs, causing suffocation.
Apply heavy dormant oil sprays only in early spring over leafless trees. However, lighter, more refined oils have been developed in recent years and can be used at other stages of growth.
Hot red peppers are among the most useful plants in the garden as well as the most flavorsome.
Grind hot peppers and mix with water and a little powdered real soap to make an infusion for spraying plants infested with aphids. Dry cayenne pepper may be dusted on tomato plants attacked by caterpillars.
However, if you note long green hornworms on tomatoes, do not be too quick to spray. Watch to see if any of the tiny parasitic wasps that build noticeable white cocoons all over tomato hornsworms are present. Do not harm these predators with sprays — they may be doing your work for you.
Ground red peppers placed around eggplants and rubbed on the leaves will help repel eggplant pests, and the dried pods, pulverized and sprinkled on corn silk, will give protection against raccoons.
Another all-purpose spray may be made of ground pepper pods, onions, and a bulb of garlic. Cover this mash with water, let stand 24 hours, and strain. Add enough water to make a gallon of spray. Use several times daily on roses, azaleas, chrysanthemums, or beans to hold down serious infestations. Do not throw away the mash, but bury the residue among the plants where insects occur.
Protect your hands with gloves when you work with hot peppers, and be very careful not to get the juice in your eyes.
Despite its ferocious appearance, this is one of our most beneficial insects, and it will not harm any vegetation in the garden, dining only on other insects. When young it eats the soft-bodied insects, the cutting and sucking aphids and leafhoppers; when fully mature it kills and eats chinch bugs, crickets, locusts, bees, wasps, beetles, flies, spiders, tent caterpillars, and many others.
Though mantids usually are found in warm countries, the common European mantid can live in the northern United States. A full-grown large mantid varies from two to five inches in length depending on the kind, yet it will easily escape notice because in form and color it closely resembles the plants on which it rests.
Female mantids lay their eggs in masses, gluing them to trees and shrubs with a sticky substance from their bodies. The eggs remain there all winter, and if you carefully examine thorny bushes, brush, hedges, and berry bushes in autumn after leaves have fallen, you may find the hardened froth mass egg cases. You can collect some from marshes and waste areas for your own garden, but never strip the area clean.
Walking stick
Praying mantis
To place them properly, allow one egg case for each major shrub or about four for each quarter acre (without shrubbery). Select a sheltered spot and tie or tape the cases securely about two to four feet above the ground.
Early in the spring the mantis will start to aid you, emerging in bright sunshine usually from early May to late June, just at the time when a large variety of insect fare is likely to be available.
Each creature is fastened to the egg by a tenuous cord that it must break. After doing so it will drop and then climb to surrounding foliage. Mantids are poor flyers and slow movers and usually remain in the area as long as they continue to find food. And once introduced, they are likely to multiply and extend control. Though many of the young may not live, still enough survive to perpetuate themselves. You can obtain mantid egg cases commercially through the mail, usually between November and early May. (See Sources.)
Onions are repellent to rabbits and may be interplanted with cabbage and lettuce. An old garden hose cut in lengths of a few feet each and arranged to look like snakes will frighten rabbits away.
Animal fat can be painted on young fruit trees, and a thin line of dried blood or blood meal sprinkled around the garden often acts as a repellent. Try a dusting of aloes on young plants, or shake wood ashes, ground limestone, or cayenne peppers on plants while they are wet with dew.
Farmers have been planting pumpkins and corn together for centuries to discourage raccoons. Put the pumpkin seeds about four feet apart. As the corn approaches maturity, the big, wide pump-kin leaves will grow around the stalks. It is believed that the coons will not come into the corn rows because they like to be able to stand up and look around while they eat, and the big leaves make that impossible.
Repellents for the corn-loving raccoon include nearby cucumber, melon, pumpkin, or squash vines. Red or black pepper on the corn silk also may help.
Other methods to control raccoons include sprinkling black or red pepper on the corn silks. This does not affect the taste of the corn.
For a small planting, a wire “corn cage” or an electric fence is sure protection. If a six- or twelve-volt battery is used, the fence will be harmless. It need be turned on only at night, since raccoons sleep during the day. Another solution is to use a small transistor radio (enclosed in a plastic bag to protect it from rain or dew), placing it in the patch at ripening time. Turn it on at night.
If the fresh tops of asparagus are crushed and steeped in water, the solution may offer protection to vegetables where root knot, stubby root, and meadow nematodes are suspected. Marigolds are also useful against meadow nematodes. (See Eelworms in this chapter.)
Root maggots may be repelled by a mulch of oak leaves.
Salt has a damaging effect on most plants and should not be used except where the soil is to be rested for a time afterward. It is useful to kill Canada thistle or quack grass and will give best results if put on after the weeds are freshly cut. Apply several times, taking care to do so only in dry weather. Salt put on slugs will dissolve them.
These beasties cause most of their damage at night in places where the ground is damp. They are topers: They love beer and will drown in saucers of it. Even empty beer cans placed in the garden attract them by their odor. They also love honey and will drown in saucers of that. What a way to go!
The skunk’s protection, butyl mercaptan, can be neutralized with tomato juice. Skunks have some benefit in keeping large insects and mice in check.
Since ordinary table salt will dissolve slugs, I find it handy to carry a small salt shaker in my pocket to use when I spot them. I feel no compunction, for these slimy creatures will destroy my choicest cabbage and lettuce heads if they get a chance.
Tobacco stem meal discourages slugs, and white hellebore controls them on grapes and cherries. They dislike tanbark or oak leaves, and wormwood will repel them by its bitterness. Snails are reluctant to cross lines of ashes or hydrated lime.
In using most sprays made from botanicals it is a good idea to add a small amount of real soap to help the materials adhere. Washing plants down with just plain soapy water is an excellent practice in many instances, for soap appears to have antiseptic qualities useful against many plant diseases. Insecticidal soaps, which can be useful against a variety of insects, are available from garden centers and by mail order (see Sources).
Some mites and spiders are natural predators, our valuable allies that dine on many destructive insects. One type of predaceous mite is used to control plant-feeding insects on avocado and citrus crops.
The garden spider is one of the best helpers to the vegetable grower.
Spider mites, also called red spiders, are apt to show up suddenly in hot weather. They sometimes can be removed from plants by spraying forcibly with a stream of plain water, and once dislodged from a plant they seldom return. A 3 percent oil spray, pyrethrum dust, or a spray of onions and hot peppers may be used, and I have found that garlic will repel the mites on tomato plants, while ladybugs are their natural enemies.
Mix tea leaves with radish and carrot seed to prevent maggots.
Since most termites cannot live without water, cutting off the source of moisture usually kills them. Silica aerogel is effective, and extracts of chinaberry will kill about 98 percent of them.
Both toads and frogs consume many insects, one toad being able to eat up to 10,000 insects in three months’ time — and many of these will be cutworms. Other pests eaten by toads include crickets, grubs, rose chafers, rose beetles, caterpillars, ants, squash bugs, sow (pill) bugs, potato beetles, moths, mosquitoes, flies, slugs, and even moles.
Horned toads, like true toads, are great friends of the gardener, devouring great numbers of insects. Help them find shelter in your garden area.
Toads do not cause warts and are not poisonous to man, though they exude a slime distasteful to their enemies. If you want to secure some toads for your garden, look around the edges of swamps and ponds in spring. Once secured, they need shelter. A clay flowerpot with a small hole broken out of the side will serve for housing if buried a few inches in the ground in a shady place. They also need a shallow pan of water and, if your garden is not fenced, protection from dogs and other creatures.
In the Southwest, we use the horned toads (really lizards) in the same way. They can withstand more heat and thrive in my garden, apparently living on dew and insects. They bury themselves in the ground during winter, emerging when the weather warms up.
See Nicotine under Insecticides, Botanical, in this chapter.
See Insect Attractants, Botanical, in this chapter.
Whitefly is one of the insects known to thrive on certain shortages of minerals in the soil, and experiments have shown that greenhouse whiteflies attack tomatoes only when phosphorus or magnesium is deficient.
Botanical controls include nasturtium, particularly good to grow in greenhouses with tomatoes. Oak leaves burned in a greenhouse for a half-hour period are helpful, and nicotine may be used as a spray.
Whitefly can be controlled biologically by a small parasite called Encorsia formosa (see Sources). Ladybugs also are a control, as are aphis lions (the larvae of lacewing flies).
White hellebore is a member of the Lily family whose roots and rhizomes contain insecticidal substances. It becomes less toxic upon exposure to light and air and has little residual effect, making it less poisonous to use than more persistent materials.
The use of white hellebore is centuries old. The Greeks mixed it with milk to kill flies, and it was a favorite remedy of the Romans against mice and rats. Today it is used to control many leaf-eating insects such as sawflies, which attack ripening fruit, and also for slugs and cabbageworms.
Wood ashes sprinkled around the base of cauliflower and onion plants are a popular remedy to control maggots. They are also used against clubroot, red spider, bean beetles, and scab on beets and turnips, as well as aphids on peas and lettuce. They are good, too, around such plants as corn, which need to develop strong stalks.
A thin paste made of wood ashes and water and painted on the trunks is used to control tree borers. A handful each of wood ashes and hydrated lime, diluted with two gallons of water, makes a spray for the upper and lower sides of cucurbit leaves to control cucumber beetles.
If woodchucks are a problem, spray the plants they are nibbling with a solution of water and hot pepper.
