50March 16, 2011
As the weather warms up, the plants in our gardens begin to wake up from their winter nap. Many of you have seen the shoots of tulips and daffodils poking up through the ground. Soon, the buds will begin to swell on trees and we will know that spring will soon be here.
As our trees and shrubs awaken, other things in our gardens will begin to awaken too. In the fall, many insects lay eggs on our trees and shrubs. In some cases, the insects hid under the bark of the trees and shrubs. In late winter and early spring, you can kill off many of these insects and their eggs with one application of horticultural oil.
As the name would imply, horticultural oil is well, an oil. It is highly refined oil. This type of oil will mix with water. Once it is mixed with water, it is sprayed onto your trees and shrubs. The oil will flow down into all of the places where the insects and their eggs are hiding. Once the oil coats the insects and their eggs, both will soon die. By controlling the insects and their eggs before they have a chance to spring back to life, you will drastically reduce the number of insects that will be attacking your plants.
There are a few things you should know about applying horticultural oil. If it is to work properly, it must be applied when temperatures are above 40 degrees. Colder temperatures will prevent the oil from flowing properly. This in turn does not allow the oil to get into all those places where the insects and their eggs hide. You also want to make sure that you apply this oil spray before the buds begin to swell. Once the buds swell, the insects are becoming active and in some cases they are attacking the buds that have begun to swell. You may also find that if you are late in applying the oil spray, you may damage the new growth.
Almost all of your deciduous trees and shrubs will benefit from an application of this spray. Most evergreens should not be sprayed with an application of horticultural oil.
Warmer weather is arriving and many of you are itching to do something in the garden. By applying horticultural oil to your deciduous plants, you will be getting out into the garden and you will be helping to get rid of many of the pests that will attack your plants.
Well, that’s all for this week. I’ll talk to you again next week.