They’re back! Remember last year when the big Joro spiders were spotted all over northern Georgia? Observant reader Michael Boylan tells me he found four webs near each other last week at Linwood Nature Preserve in Gainesville. “It’s easy to know a Joro web,” he said. “They are big and really ‘messy’ looking. The Christmas freeze may have killed some but by no means all of them.” Remember, Joro spiders are here to stay, they don’t harm humans or pets, and we don’t know yet what part they are playing in the environment. If you don’t like them on your property, it’s safer to wind the web on a stick and toss it away than it is to spray insecticide.
Q: I read your online article that said it takes a short amount of time in a composting facility for urushiol (the oil in poison ivy) to lose its potency. How long does it take for shredded poison ivy leaves to lose their potency in normal outdoor conditions? Matt Best, Harrisburg, Pa.
A: I was wrong back then! I forgot that urushiol is an oily lacquer and is not easily dissolved by water. Rainwater will wash it away eventually, but it will take a long time without the help of another solvent. Effective solvents for oily lacquers include alcohol and hot soapy water. In a home compost pile, urushiol can cause irritation in sensitive individuals for at least a year. In your lawn, urushiol will be broken down by sunshine and rain but not much else. Shredded leaves would rot in about a month, but the urushiol would still be where they were. Bottom line: Be cautious wherever you encounter poison ivy and don’t let the oil touch your skin.
Q: I just noticed a powdery gray ash on my tall fescue sod. Is this possibly slime mold? Shane DeLong, Towns County
A: It sure is! Slime molds are primitive organisms that grow on the surface of grass. They do not hurt grass beyond some yellowing. They often appear on well-maintained turf after a warm summer rain. A slime mold is composed of thousands of tiny, usually purple, gray, white or cream, sack-like fruiting bodies. These form in 4- to 6-inch patches in the turf and may be widely spread or clustered into groups. The slimy growth is called a plasmodium. This dries into a powdery mass of spore-bearing bodies that coat the grass blades. Control measures are usually not necessary; but if desired, slime mold can be removed by mowing, or hosing the spot down with a fast stream of water.
Email Walter at firstname.lastname@example.org. Listen to his occasional garden comments on “Green and Growing with Ashley Frasca” Saturday mornings on 95.5 WSB. Visit his website, www.walterreeves.com, or join his Facebook page at bit.ly/georgiagardener for his latest tips.