Catalpa Trees Need to Be "Seeded"

Q: The ugly catalpa tree at our Nearly Native Nursery has always had the fish bait worms. We have several customers who have purchased trees from us but still no worms for them. How do they attract them? Debi Rodgers, Fayetteville

A: Catalpa caterpillars (“worms”) come from eggs laid by the catalpa sphinx moth. Once they mature, the caterpillars pupate in the soil near the tree. You should sell a few of your caterpillars with each tree and instruct the buyer to let the worms feed and pupate, thereby "seeding" the tree with future fish bait.

Q: What do you think about using beneficial nematodes for soil pests? Are they effective and safe? L. A. Ricketson, Buford

A: Insecticidal nematodes are a great concept but getting them to perform as advertised is a tough job. These tiny soil worms are typically sold in a dormant state on a piece of sponge. You soak the sponge in water to activate the nematodes, then apply the water to the area where you need insect control. Problems arise, though, in determining if you are getting live nematodes on the sponge and if they survive after being applied. These creatures require moist soil and an abundance of host pests in order to stay active. Otherwise they die off. In my view, they work better in greenhouse situations rather than for grub or flea control.

Q: You say on your website that aspirin can prevent disease on tomato plants. Where can I find more information about the process? Daniel Mullinax, e-mail

A: Scientists have known for several years that certain compounds can signal a plant to defend itself against pests before a disease or insect actually arrives. One of these compounds is salicylic acid, a breakdown product of aspirin. Gardeners have experimented with spraying their plants with aspirin water with varying degrees of success. One project with tomatoes found that sprayed plants had more but smaller fruits. You are welcome to be a citizen scientist too. Use 250 mg. of aspirin per gallon of water, maintain an identical control group and report your findings back to me!

Q: Can I split my liriope and replant it without waiting for dormancy? Lynne Terrell, e-mail

A: You can split liriope 24/7/365. Freezing temperatures and hurricane rains might deter the gardener but liriope will prosper no matter what conditions you move it in. I transplanted some ‘Peedee Ingot' golden monkey grass in the heat of July and forgot to water it for a week. It forgave me and is now an attractive border to a hydrangea bed.

Q: I always put down a weed block between garden rows and cover it with mulch. But it takes considerable time to remove old mulch and weed block and then apply new stuff again each year. Could I cut carpet into strips to block weeds? Rich Mickiewicz, e-mail

A: I’ve seen carpet used to prevent weeds between garden rows many times. It works great! You’ll need to replace it every few years as it deteriorates but it makes sense to recycle carpet this way.

Listen to Walter Reeves Saturday mornings on AM 750 and 95.5 FM News-Talk WSB. Visit his website,, or join his Facebook Fan Page at for more garden tips.