Foundation sprays, leaf diseases, tomato care

By John Fulton

[May 27, 2011]  Foundation sprays -- If you have been following a foundation spray program all year, keep it up. If you haven't been, it is probably time to start. The foundation spray program is your first line of defense against nuisance pests in the house. It cuts down on crickets, millipedes, spiders, ants and many others that find their way inside. And, with the crickets singing, it's only a matter of time before they find their way into your abode.

To accomplish a foundation spray, you would select a material such as permethrin or bifenthrin to begin with. Then spray the foundation and the adjacent foot or two of soil or plant material with the spray mixture. Both these products are cleared on most types of plants. Foundation treatments should be applied every seven to 15 days, depending on the temperatures. The materials break down quicker in hot weather.

Foundation treatments won't prevent everything from getting in the house and certainly won't kill things already in the house. For insects already in the house, you have a few options. The first is mechanical control. This is fancy language for something like a fly swatter, shoe, vacuum cleaner, flypaper or glue boards. The next is chemical control. This basically means aerosol cans inside the house. The most common ones are for flying insects or ants, although many of the flying insect killers now have permethrin in them and can last quite a while.

Leaf diseases accelerate

As mentioned last week, fungal leaf diseases are present. They are now making their presence felt with a vengeance. These diseases infected trees and shrubs earlier and have continued to develop rapidly. Adding insult to injury, we had extremely high winds affecting the tender leaf tissue, especially on maple trees. Some trees are now to the point of being, well, leafless.

Anthracnose is the No. 1 fungal disease of good-quality shade trees, and apple scab is starting to hit apples and crab apples.

To give a brief overview, these diseases are preventable but not curable. They are seldom life-threatening to the tree or shrub, but they can make things look rather unsightly. Many shade trees losing a large percentage of their leaves will set another set of leaves within four to six weeks. Apples and crab apples are less likely to set new leaves, but it sometimes happens.

Anthracnose has different stages depending on the time of infection. There is a bud stage, when buds are killed as they begin to open. Next is a leaf stage, which affects only leaves. This stage is the one we are commonly seeing, and it infects leaves and gradually consumes the leaf. And the other stage is the twig stage, which affects smaller twigs on trees and shrubs. This is one reason why sycamore trees tend to have so many small branches break. The infection leaves a brittle scar on the branch, which makes it susceptible to breakage.

There is actually a specific anthracnose disease for each shade tree. This means sycamore anthracnose, maple anthracnose and so on.

As I mentioned, once infection has occurred, it can't be cured. The prevention part needs to begin with a regular spray program similar to what is used for production apples. This means starting when the leaves are just out of the bud in the early spring. The same kind of timing applies to ornamental trees.

The main harm caused is the loss of food produced by the lost leaves and the loss of energy in forming another set of leaves. Fertilizer application at the lawn rate, to supply a pound of nitrogen per 1,000 square feet broadcast, will help the tree as much as anything.

Tomato care

With the widely fluctuating amounts of rainfall, blossom-end rot is definitely a possibility. It has even started on some container-grown tomatoes. The best solution is to mulch tomato plants to help even out the moisture supply and help keep the roots cooler. This problem is caused by uneven calcium amounts in the plant. Addition of lime when you see the problem usually isn't as effective as evening out the moisture flow for the plant by mulching. Any material will do (grass clippings, straw, commercial mulch, etc.), with 2 inches being adequate and 4 inches being better. You may have to compensate with a small amount (emphasis on small) if you use items that decompose quickly -- such as grass clippings.

[By JOHN FULTON, University of Illinois Extension]