Editor’s note: Kelly R. Jackson takes questions called into his phone recently at the Christian County Extension Office and answers them in the Garden Corner column.
Question. What do you call the big yellow-and-black spider I find in my garden?
Answer. The black-and-yellow garden spider often seen in early fall is called the golden argiope. This orb weaver makes a flat, wheel-like web with silk lines
radiating out like spokes from the center. Webs are usually in sunny overgrown areas where tall grass or brambles can support the web structure, which may be up to 2 feet across.
The black and yellow garden spider likes to hang head down in the center of its web. While resting, the spider often holds its legs together in pairs so there seems to be 4 legs rather than 8.
Because of poor vision, the spiders rely on vibrations of trapped victims to indicate that their web has captured a meal. These spiders may take prey that is as much as twice their size by using their long legs and silk to efficiently immobilize the struggling meal.
A zig-zag or zipper pattern from the center to the bottom of their web has led to them being referred to as “writing spiders.” The “zipper” was once thought to provide structural stability to the web or to attract flying insects. Another idea is that the zipper provides the web higher visibility so that birds are less likely to fly through and destroy the web. The black and yellow garden spider is not aggressive but may bite if harassed. The bite is
reported to be similar to the pain
of a bee sting.
Q. Should I mulch my garden with hay or straw or does it matter?
A. Both hay and straw can be used in gardens to suppress weeds from emerging from seed and to conserve moisture. Mulch is usually applied to gardens after vegetable crops are well-established and the soil temperature is optimal for growth.
Both hay and straw when left on the garden to break down, help to
build soil organic matter.
Hay is more likely to introduce new weed seeds compared to wheat straw, which should be mostly the stalks of wheat. However, hay, especially with legumes like clover, adds nitrogen to the soil. That nitrogen is good for plants but may also trigger some weed growth. Neither hay nor straw tie-up soil nitrogen levels unless they are incorporated into the soil. Also keep in mind that applying mulch too early in the season could lower soil temperature and slow the growth of some vegetable crops, giving weeds a head start.
Kelly R. Jackson is the Christian County Extension Agent for horticulture. He can be reached at 270-886-6328 or visit Christian County Horticulture online at www.christiancountyextension.com.