Q: What can I spray to kill weeds in and around my rose bushes without hurting them? Estelle Cooper, Jefferson
A: At a big-box store I recently saw a sprayer that had a conical shield attached to the spray wand. The label indicated it was for use near ornamental plants. You can make a homemade shield by cutting the neck of a four-inch plastic funnel so that it fits over the nozzle of your own garden sprayer. Use tape to hold it in place. Or you can cut the bottom off of a gallon milk jug, put the jug over a weed and give it a squirt through the jug neck. With this protection, I’d feel comfortable spraying glyphosate (Roundup, etc) as close as 12 inches from your rose stems. You could also use a large piece of cardboard to shield plants when you spray.
Q: A neighbor swears by nicotine tea to spray for insects in his vegetable garden. He takes a wad of chewing tobacco wrapped in cheesecloth and lets it sit in a gallon of water for a week then uses the liquid in his sprayer. Is this a good alternative to chemicals? Lou Lunetta, email
A: I saw the same insect-control method used in Cuba. They soaked tobacco leaves in a bucket and sprayed the resulting tobacco water on their vegetables. I noted that the gardener spraying it was careful to wear rubber gloves and rubber boots when he used the stuff because nicotine is quite poisonous. I understand that you don’t want to use “chemicals” in your garden, but several manufactured insecticides are less toxic to use than nicotine. Instead of tobacco water, consider using brand-name insecticidal soap or pyrethrin insecticides in your garden and plant lots of flowers to attract beneficial insects.
Q: What can we plant to repel mosquitos instead of using chemicals? Steve Houlder, Newnan
A: I hate to burst a popular bubble but no landscape plant has been shown to repel mosquitoes. It is true that the sap of some plants is mildly repellent but few gardeners want to use a kitchen juicer to make their own mosquito deterrent. If you’ve emptied water containers and eliminated English ivy hiding places, consider a non-oily repellent that contains picaridin. Another way to keep mosquitoes at bay on your deck or patio is to use an electric fan. A constant gentle breeze is more than most mosquitoes can fight.
Q: If I raise the soil level around my trees about two feet, will they die? Leona Mosby, email
A: If you cover your mouth and nose with a wet washcloth, will you find it hard to breathe? Tree roots require the ability to “breathe.” They need to get rid of harmful gases generated in the normal process of root growth. They also need access to oxygen and carbon dioxide. In general, raising the soil level more than six inches harms tree root respiration, particularly if most of the roots of a tree are covered. If you want to grow flowers under the tree, consider using planters held above the soil on short legs.
Listen to Walter Reeves Saturday mornings on News 95.5 FM and AM750 WSB. Visit his website, www.walterreeves.com, follow him on Twitter @walterreeves, on Pinterest, or join his Facebook Fan Page at bit.ly/georgiagardener for more garden tips.