Bug Control: Can it Really Be That Easy?
At least one of the culprits for leaves curling up (and the one best fixed with the water) are Aphids.
Aphids, also known as plant lice, are roughly 1/10th of an inch long. The most common colors are green and black, and they can weaken a plant, stunt its growth, and cause the leaves to curl or wilt.
Amazingly enough a strong shot of water is often all that is required to wash them from the leaves of the affected plant.
The leaves of the elm tree are curling up. The leaves on the locust tree are turning yellow. The experienced exterminator would immediately say, you have bugs, and possibly describe the type with the given suggestions being an expensive and environmentally invasive procedure (the smell of most commercial pesticides is often enough to knock you over). So what are the alternatives? If the bugs are only affecting the leaves, there is a very simple alternative.
Many years ago I noticed this problem on the trees around our house, and the solution posed by our landlord was to let the bugs kill the trees and then cut them down. Since we didn’t want to loose the trees, I checked a book out of the library on organic gardening and learned that many bugs, particularly those that affect the leaves can be removed by simply washing them off of the trees. I asked a friend that ran a yard care business if it could really be that easy, and he said that you didn't even have to use soap, simply spraying the undersides of the leaves with water would knock most kinds of bugs from the trees.
With nothing to lose, I gave it a try spraying the trees about once a week. The first time I could see the bugs falling from the leaves in hoards. I found that an adjustable nozzle (a pistol style) worked best allowing me to hit the highest branches with a full jet and the lower branches with a lighter jet. Then I made sure to walk all the way around the tree, making every effort to hit all of the leaves I could, especially the upper leaves and the ones that looked the worst.
After a few weeks the leaves were growing back normally and for many years after that a bit of preventative maintenance (spraying the tree every three or four weeks beginning mid-spring) kept the trees bug free and healthy, especially during the summer heat when the extra water wouldn't hurt anyway. Can it really be that simple? Everything I've read since then confirms what I learned through experience. For most bugs that affect the leaves, spray the underside of the leaves of the trees regularly with water, and the bugs will stay away. It really is that easy.