WSU Extension Q&A: Codling moths will destroy apples

Q. I am new to this area, and I was told not to plant an apple tree because of the codling moth. What is the codling moth and what does it do to an apple tree?

A. Codling moth is an insect that causes large economic losses in commercial tree fruit. Homeowners are required to control this pest with pesticides or exclusion (bagging individual apples). The larvae burrow into the apple and leave small, round, brown frass near the entrance hole. Without proper control, we would have the iconic ‘worm in the apple.

Q. I try to garden organically. My lawn has crabgrass in it, but I do not want to use the chemical crabgrass preventers. I have heard that there is a natural product made from corn. Will it work for crabgrass control?

A. CGM, or corn gluten meal, marketed under the trade names of WOW or A-Maize-N, is a byproduct of corn processing to make cornstarch and corn syrup. It does not prevent crabgrass from germinating, but causes the newly emerged roots of a young grass plant to dry out and die. It is often part of an organic weed control program, but research results show its effectiveness is greatly inconsistent. University experts recommend trying it in a limited area before spending the money to apply it to your entire lawn.

Crabgrass is encouraged by poor lawn health, low mowing and frequent shallow watering or excessive watering. Avoid these practices and work at applying adequate amounts of nitrogen fertilizer to promote healthy, dense growth that prevents crabgrass growth.

Q. Last week, I was looking at tomato seeds at the store, and I am confused by the two types of tomatoes you can grow, determinate and indeterminate. What is the difference?

A. Determinate tomatoes are small, compact plants that grow to a certain height, then flower and set all their fruit within a short time. The harvest period for determinate tomatoes is generally short, making them good choices for canning.

Indeterminate tomatoes continue to grow, flower and set fruit until killed by the first fall frost. Thus, the harvest from indeterminate varieties often extends across two or three months. Yields are generally heavier than determinate types, but are usually later to mature. Indeterminate tomatoes are tall, sprawling plants that often perform best when supported by stakes or a tall wire cage.

This story was originally published March 5, 2016 at 11:58 PM with the headline "WSU Extension Q&A: Codling moths will destroy apples."