Gardening with Allen: Safer ways to control insects
By Allen Wilson
Published: May 21, 2022, 6:00am
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Close-up of rose stalk with lots of aphid
I have some insect problems that I would like to take care of without poisoning my family and pets with dangerous chemicals — specifically, slugs in my newly planted flowers and vegetables, worms in my broccoli last year, aphids on my roses, lace bugs on my rhododendrons. Are there organic insecticides or other safe ways to control these and other insect problems?
There are some tools and organic insecticides that can be safely applied in your landscape.
A safe replacement for the old snail and slug bait that contained metaldehlyde has the active ingredient iron phosphate, which is not toxic to humans or animals. The most popular brand is Sluggo.
Aphids and spider mites are easily washed off plants with a solution that contains dish soap. You can make your own solution or purchase insecticidal soap.
Consider delaying treatment if you notice beneficial insects, such as ladybugs. One time I walked under a tree that was so badly infected with aphids that it was dripping with aphid secretion. I did not have time to take care of it at the time. Two days later, the tree was completely free of aphids. Ladybugs had cleaned them out.
Three organic pesticides are available that control most insects without leaving dangerous residues on the plants. My favorite is Spinosad, an organic pesticide effective against lace bugs, worms, leaf miners and many other pests.
Neem oil is another natural pesticide. It not only kills aphids on roses but also controls three rose diseases, including black spot. Bacillus thuringiensis (Bt), sold as Thuricide or Dipel, is effective against worms in plants of the cabbage family, including broccoli.
There is one other product that is very effective in preventing damage from several vegetable pests by preventing the adult flies or moths from laying their eggs on the plants. Floating fabric row covers are lightweight blankets made of spun bonded polypropylene. They are permeable to air, sunlight and rain. Floating row covers are placed loosely over newly seeded or transplanted vegetables so they have room to grow. Soil is placed around the edges to hold them in place. Vegetables can be watered and fertilized without removing the row covers. They do need to be folded back for weeding.
Row covers also trap warmth around the vegetables and protect them from wind damage, so early growth is improved.
