We need to ask a gardener to apply an insecticide to a CHERRY tree. Neighbours have complained about the tree being infested by insects.
For reasons I cannot go into, there is no regular access to the tree. So we want to ask someone to come once and apply some kind of insecticide.
We want it to be organic – so no adverse effects on other wildlife and humans. What would be a sensible option in this scenario, i.e. what should we ask the gardener to do/apply?
Many thanks.
Hmm, that's impossible I'm afraid. Anything 'organic' isn't usually systemic, and you'd need a systemic pesticide for any lasting effect, and even then, depending on the product used, the average length of time for the product to still be having an effect will be around a fortnight.
As for which product to choose, rather depends on a few things, that is, what part of the world you're in, which insects are infesting it (cherry aphid?) and whether the cherry tree is a fruiting one, producing edible fruit, or a purely ornamental one.
Usually around this time of the year, many gardening/nursery stores carry and sell beneficial insects, such as ladybugs and praying mantises. You can even order them online. Adult ladybugs can eat up to a 1000 aphids a day and as a larvae, about half as many.
Release some of them around the base of the tree after the sun goes down, so they stay put, because they only fly during the day. You mentioned only being able to apply once, but for better results, release some over the course of a few days.
When stored in your refrigerator, ladybugs can last weeks.
