Dear Neil: How can I eliminate Mexican petunias? They are so invasive. A: A broadleafed weedkiller (containing 2,4-D) will kill a certain portion of them, but at some point, you may just decide to rototill deeply and rake out as much of the root system as you can. Another option would be to lay a weed-blocking fabric over the bed for a year or two.
Put bark mulch over it to conceal it. They will gradually give up. Dear Neil: I have a 6-year-old pear tree that has fire blight.
I have two other pear trees and three apples. How can I keep the one tree alive, and what can I do to prevent spread of the disease? A: The past few years have been really rough for fire blight. The fact that only one of your five trees came down with it is encouraging.
Prune out the dead branches on the pear. Make each cut back into healthy tissue, disinfecting your pruning tools between each cut by washing them with a solution of 90 percent water and 10 percent chlorine bleach. Spray all the trees with agricultural streptomycin while they’re in full bloom.
It’s available at many full-service nurseries and farm supply stores. You might want to locate it over the winter and have it on hand. Dear Neil: I have about 30 hibiscus plants, and they are covered with whiteflies.
One nurseryman suggested Malathion, but another warned me that it would burn my hibiscus plants. I’ve also used a systemic, but I still have them. What works? A: Whiteflies are in love with tropical hibiscus plants.
Added to the fa.