Biological Control

The theory behind biological controls is that methods for control of pests can be found within nature. These methods are safer to humans and less damaging to the environment than commercial insecticides. Gardeners have many forms of biological control at their disposal, including companion planting, use of predators, and sprays made from plant extracts or ground-up insects.

Companion Planting

Some plants, including marijuana in its later stages, produce resins or essences which repel or kill plant pests.

Some of them are general repellents that affect a broad range of plant pests; others affect specific species.

Generally, the heavily scented plants, such as spices, mints, and other herbs, are most likely to have these qualities.

Some of the more familiar plants used to protect gardens are the Alliums, or onion family, with garlic, chives, green onions, and other oniony-type plants as members. This group repels a broad range of plant pests such as aphids, spider mites, flea beetles, potato bugs, bean beetles, and many other insects, as well as rabbits and some deer. They are easily planted around the garden or between the marijuana plants. Just plant onion bulbs or the cloves from a garlic bulb so that the top of the bulb is about one inch deep. One garlic bulb yields quite a few cloves; so a large garden requires only a few bulbs.

Geraniums are reputed to repel leafhoppers and many kinds of beetles. These plants prefer a dry soil, thrive in full light, and usually grow two feet tall. Geraniums should be interspersed with the marijuana, or potted geraniums can be set out if problems develop. Tansy (Tanaetum vulgare) is a tall, fragrant, woody perennial which grows five feet tall. It protects against cut-worms, beetles, cucumber beetles, and other eaters and borers.

Mints repel many insects and are sometimes used as mouse repellents. They are especially useful for the control of the flea beetle. They thrive in semi-shaded areas with rich soil.

Marigolds can be planted to eliminate nematodes. They are fast-growing annual plants which flower profusely.

They come in many varieties, ranging in height from six to 30 inches. They grow in a wide range of soils and do best in the sun. The scented varieties - usually nonhybrids - offer the most protection.

All companion plants must be planted close to the plants to be protected, since their repellent qualities spread only a short distance beyond their circumference. They are effective when they are planted before the

damage is apparent, and offer long-tern protection. They are used when a pest is expected. For instance, growers in the San Francisco Bay Area expect rose leafhoppers to attack their plants. Since geraniums grow in the area as perennial plants, some growers plant them permanently in the garden. As the geraniums develop into small bushes, the hoppers leave, never to return.

Predators

Many of the insects in your garden are called beneficials, because they perform a useful service in the garden. Some of them eat decaying matter; others help in the pollination process; and some pry on insects which damage crops. Almost everyone is familiar with the ladybug, which eats aphids and insect eggs and has a voracious appetite. They are available commercially by the pint. The praying mantis eats slow-moving insects. When it first hatches, it starts out on aphids and mites. But as it grows larger, it eats bigger insects and worms. Mantis-egg cases are foam-like, straw-coloured masses which contain 100 to 300 eggs. These cases are sold commercially but can also be found in the late fall in bushy areas. Another insect which is sold commercially as a plant protector is the green or brown lacewing. It has golden eyes, looks fragile, and flies erratically. But in their larval state, lacewings eat thrips, mites, caterpillar eggs, scale, leafhopper nymphs, aphids, and mealybugs. The trichogamma wasp is an egg parasite which lays its eggs in the eggs of over 200 species of insects, including many moths and butterflies which hatch into worm pests. Cryptolaemus is used to destroy mealybugs. Adults are released when mealybugs appear in the spring. They seek out the

colonies and lay their eggs. When the eggs hatch the larvae wander around the infested area and eat the young mealybugs.

The use of commercially bred or gathered predators is most feasible in large gardens or fields. The insects may not have much effect on small gardens, since they wander off to find food and may never return. Try to buy from manufacturers who intentionally do not feed their product before shipping. Hungry predators are more likely to stay and eat the pests.

Insects are just one groups of predators. Birds such as purple martins, robins, blue jays, chickadees, and even starlings and English sparrows eat large quantities of insects and other small pests. They can be attracted to the garden by placing a feeder, bird houses, and water in the area. When plants get larger, some gardeners let chickens, ducks, or geese run through the garden. In a short time, they pick it clean of pests and weeds. Reptiles and amphibians, including frogs, toads, snakes, lizards, and turtles, all eat garden pests and should be encouraged to make a home in the garden.

Homemade Repellents and Insecticides

Another way to control garden pests is to make sprays from plants which repel insects by using a juicer or blender or by baking a tea. Ingredients can be found in most kitchens. Chile pepper, garlic, coffee,

horseradish, radish, geranium, and tobacco are the usual mainstays of herbal sprays, although most strong-smelling herbs and spices have some repellent qualities. Many gardeners experiment to see what works in their garden. For instance, if an insect which bother marijuana stays clear of a nearby weed, a tea or blended spray made form that plant may control the pest. But try it on only one plant (or part of a plant) first, because the spray may also be harmful to the marijuana.

Garlic is probably the most popular ingredient for general-purpose sprays made from kitchen ingredients. A typical formula is to soak three ounces of chopped or minced garlic in a covered container of mineral oil for a day. Then, slowly add a pint of lukewarm water in which a quarter ounce of real soap (Ivory will do) has been dissolved. Stir and let stand several hours, than strain. Use as a concentrate, adding between 20 to 100 parts water to one part concentrate.

Other recipes call for boiling the garlic or for grinding or juicing it. Some brewers add other spices to the basic formula. One recipe calls for one clove garlic, three cayenne peppers, one onion, a quarts ounce of soap, and sufficient water to blend. Let it sit for three or four days before using, and use one part concentrate to 20 parts water. Homemade tobacco teas are sometimes used as insect sprays. Use one cigarette in a quart of water.

Let it brew 24 hours before using.

Snails and slugs are attracted by yeast solutions, which are easily prepared from cooking yeast, sugar, and water. This is also why gardeners have success trapping these leaf munchers in bowls of stale beer. Place deep-sided containers at the soil level. The pests slide in and drown.

Gardeners should not overlook handpicking as a viable method of pest control. The foot or a quick thumb and forefinger can eliminate large numbers of pests and can keep a small garden pest-free. Collect the bugs and drop them in a tin can with some alcohol to kill them. Early morning is the best time to collect pests, since they are slower-moving until the sun warms them.

Snails, slugs, earwigs, and some other insects gather in cool, moist areas during the heat of the day. By providing just such a space in a garden, many of these pests can be located and destroyed. Place pieces of cardboard or boards around the garden; look under them each day.

Home Remedies

Gardeners and farmers have discovered and invented ingenious ways to control insects without harming the environment. Some of the more popular ones are listed here, but there are many more, each suited to a particular situation.

Soap and water is an effective control measure for mealybugs, mites, leafhoppers (nymph stage), leaf miners, and aphids. Simply wash the plants thoroughly with a solution of two tablespoons of soap dissolved in a of water. Rinse the soap off thoroughly. (Some growers feel that the addition of kerosene or alcohol makes the solution more effective, but these can harm the plants and dissolve THC.) This treatment does not eliminate all of the pests, and may need to be repeated weekly, but it does keep them under control.

Sprays are sometimes made from healthy insects, which are caught, ground up, and then sprayed back onto the plants. When the pests come in contact with the spray, they become infected with the pathogen and get sick. This method is very effective, and is considered safe, but it is not easy to capture sick insects. A in this technique was described in the October 1976 Organic Gardening and Farming Magazine, in which a spray was made from healthy insects. In a followup article in the May 1977 issue, the authors theorised that any population of insects contains pathogens. If enough insects are collected, some of them are sure to be sick, and they contain enough germs to spread the disease. To make an insect spray, capture about a hundred pests. (Make sure not to include any beneficial insects or the spray may also work against them.) Using a blender, mix them with a cup of spring water, strain, and dilute with enough water to spray your garden.

Whenever making or storing sprays, use a glass container. Metal or plastic ones may react with the chemicals that the liquids contain.

Another home remedy for the control of mites and aphids is a mixture consisting of a half cup of milk in four cups of wheat flour, added to five gallons of water. When it is sprayed on the undersides of the leaves, it suffocates the insects and then flakes off as it dries.

Some growers use mulches to control insects. Cedar chips repel beetles, moths, mites, and mealybugs.

Aluminium foil is used for aphid and thrip control on small plants; the reflected light disorients them and they do not land on the plants. A sprinkling of cream of tartar eliminates ants, and boric acid kills roaches. Sulfur powders, available at nurseries, are used to control mites and fungus infections.

Organic Insecticides

Pyrethrum, rotenone, and ryania are effective insecticides which come as powders (dusts) or sprays. They concentrated form of naturally occurring plant substances, and are considered harmless to warm-blooded animals when used as directed.

Ryania, which is found in the roots of a tropical shrub, is most effective against chewing insects, worms, and larvae, which it incapacitates, rather than kills.

Rotenone is a general-purpose insecticide with little residual effect; that is, it breaks down soon after application, and is therefore one of the safest insecticides. Two or three dustings during the seedling stages afford protection against most insects and bugs.

Pyrethrum is one of the most powerful natural insecticides, and is effective against a wide range of pests. It is also relatively nontoxic to bees and ladybugs. Pyrethrums are found in the pyrethrum plant as well as in chrysanthemums. They are non-persistent, and in small doses may make the insects sick without killing them.

These insecticides are available at many nurseries and may provide the surest, easiest form of protection against serious insect attack.

Barriers and Traps

In gardens and small farms, insects and other pests are sometimes controlled by the use of traps and barriers that prevent them from reaching the marijuana. When the plant are young, they can be protected from

cutworms, caterpillars, snails, and slugs by a collar that is buried an inch into the ground and is six inches high. Some growers face it with aluminium foil, which many insects seem to dislike. One ingenious grower painted collars with molasses to capture the crawlers. She also caught a significant number of leafhoppers.

Commercial stickums such as Tanglefoot can also be used to trap insects.

Snails, slugs, and some crawling insects are repelled by a border perimeter of lime, potash (wood ash), sulfur, sharp sand, or cinders. Place a thin layer, six inches wide, around the perimeter of the garden, or around plant. Flea beetles and some other flying insects are repelled by wood ashes dusted on the leaves. The powders are water-soluble; so they should be replaced after a heavy rain. Crawling pests sometimes have a hard time reaching plants grown in containers or raised beds.

Flying insects, such as leaf and treehoppers, can be prevented from getting to plants by barriers made from cheesecloth. Other growers place cardboard sticky with glue between plants, and then shake the plants. The cardboard catches a good proportion of them. One innovative grower in Palo Alto, California, placed a furniture crate, with the top cut off and with Tanglefoot spread on the inside, around each of his six plants. He said that by shaking the plants, he eliminated leafhoppers in four days.