Last year leaf miners ruined my lettuce and maggots ruined my radishes. Is there any control for these pests that does not leave dangerous chemical residues on my food?
Yes there are two wonderful organic pesticides which are completely safe to use on food crops and around children, pets and wildlife.
Spinosad is a compound derived from a bacterial species originally found on sugar cane. It is an organic pesticide which can be used for cat fleas and agricultural food crops.
It controls a wide range of insect pests including leaf miners, root maggots, borers, caterpillars, codling moth (apple worms), beetles, thrips and many more insects.
For leaf miners on lettuce and other leaf vegetables, spray the leaves at the first sign of damage. Repeat application at weekly intervals.
For root maggot control, spray the soil around plants of radish and other root crops as soon as seedlings emerge from the soil. It can also be sprayed over seeds before they are covered with soil.
To prevent wormy apples, begin spraying fruit as soon as it reaches the size of the tip of a finger and repeat every two weeks.
Spinosad will also control insects on roses and other woody ornamentals including borers and caterpillars on trees.
The word “spinosad” might not be on the main label. You may have to check active-ingredient lists to find it.
Spinosad will most likely be available at full-service nurseries and garden stores.
Neem oil is another organic pesticide derived from the neem tree. It is effective in controlling major insects as well as a number of leaf diseases. It is my favorite pesticide for roses since it controls both insects and diseases. Spray every two weeks on roses to prevent mildew and other leaf diseases.
Other organic fungicides for plant disease control include sulfur, copper and horticultural oils.
Allen Wilson is a Vancouver gardening specialist. Email him at allenw98663@yahoo.com.
