Tips for recognizing and managing garden pests
For flea beetles, aphids, mealybugs, spider mites, thrips and whiteflies:
Mix one cup of vegetable oil with one teaspoon of mild liquid dish washing or insecticidal soap. Shake well or mix with a stick blender, then add a quart of water. Spray.
Mince one and a half bulbs of garlic and soak in three teaspoons of mineral oil for 24 hours. Strain into two cups of water, add one teaspoon of mild liquid dish washing soap and shake vigorously. Spray.
For chewing and sucking insects, aphids:
Puree two small onions and two cloves of garlic. Add a chopped jalapeno pepper or one tablespoon of cayenne pepper. Soak in one gallon of water overnight. Strain. Extra can be refrigerated for two to three weeks.
Put flat beer into a plate and the slugs will become drunk and drown. Pick the slugs up and throw them out or pour salt on them.
After having grapefruit for breakfast put the empty halves into the garden in the evening. The slugs will climb in because of the scent and they wonÕt be able to climb back out.
Mix one tablespoon of mild liquid dish washing detergent or insecticidal soap with one teaspoon of baking soda and one quart of water. Mix well.
For blackspot, powdery mildew, brown spot and other funguses:
Mix one tablespoon of canola oil with four teaspoons of baking soda or potassium bicarbonate. Pour into one gallon of water and shake vigorously. Spray the plant but do not pour onto the soil.
For leaf spot
Puree two cups of tomato leaves and mix with two tablespoons of cornstarch in 10 cups of water. Strain.
Plants to the rescue of plants
“Maybe it’s because of their wine-making heritage, but the French are obsessed with fermenting various plants into special insecticidal, bactericidal, and fungicidal brews to use on…other plants.”
Information on growing and brewing your own pest fighting plants from a French gardening site
Elderberry as natural insecticide
Elderberry leaves, roots and bark have been used for centuries to kill pests on plants. However, the toxins that kill pests are also dangerous to humans. Elderberries contain high levels of chemicals (alkaloid and glycoside) that breakdown to cyanide. Use gloves when handling.
Common elderberry (Sambucus nigra): Large shrub to small tree
Active ingredients: Sambucine
Action: Powerful repellant; fungicide
Preparation: In decoction, two pounds of leaves soaked for 24 hours in 2.5 gallons of water, then boiled for 30 minutes. Spray undiluted against aphids, beetles, caterpillars. In fermented extract, use two pounds of fresh leaves in 2.5 gallons of water. Use undiluted against shelf fungus infections on trees.
More information on elderberries from Steve Brill
European paper wasp
The European paper wasp has wiped out nearly the entire butterfly/moth population along the Front Range urban corridor. Since large moths are among our best pollinators, this removes yet another important pollinator from our gardens. With honeybees in jeopardy and native bees declining in numbers, the plight of pollinators is serious.
Whitney Cranshaw’s info on the European paper wasp