The leaves on my two pear trees are developing black splotches, and then they're falling off. The fruit is fine, and I know it's not fire blight, because I'm 83 years old and spent 52 years on the farm.
Is this some new disease?
Sounds like the combination of heat and drought is getting to your trees. Ornamental pear trees, like the Bradford, are also exhibiting similar symptoms this summer.
Pear leaves tend to turn black during periods of drought and high heat, especially near the leaf tips and margins. Continue to keep trees well watered. Water the root zone deeply (out past the canopy).
Pesticides will produce similar symptoms on fruit trees if they are applied during hot, dry weather. (See checklist item.)
On some of the trees in my yard, I'm noticing twigs and branches that are losing leaves and looking dead. Should I prune them out now?
This summer's drought is taking a toll on landscape plants, including mature trees.
Before getting out the pruning shears, though, you should scrape away the outer bark of those dead-looking branches with a sharp knife to see if the underlying tissue is still green. If you see green, that means the tree branch is still alive and will recover.
If you have any question about whether a particular branch is still viable, wait until the trees leaf out in the spring. Regrowth means the branch is OK.
Strange-looking green and black insects with black legs are running all over my squash plants, and the leaves have white speckles all over them.
Please identify these unwelcome invaders and tell me what I can do about them.
You're noticing squash bug nymphs.
These pests hatch out from copper-colored eggs that you may have noticed on squash leaves, stems, blossoms and fruits. The bugs turn from black to brown as they reach the adult stage and attain a length of a half-inch. Adults emit a strong odor when crushed.
The nymphs and adults suck plant sap, leaving small white or yellow spots.
Botanical insecticides containing pyrethrum and soap or neem should be effective on the nymphs. Also, look for and destroy eggs before they hatch.
Garden tips are provided by the Home and Garden Information Center of the Cooperative Extension Service of the University of Maryland. For more information on these questions, or if you have questions of your own, call the center's hot line at 800-342-2507 or visit its Web site at http: //www.agnr.umd.edu/hgic.
Checklist
* When vigorous tomato vines grow over the tops of stakes or cages, they can be trimmed back with lopping shears. This will not diminish your harvest.
* Remove all blackberry and raspberry canes that fruited this summer. Also, prune out and discard all dead and damaged canes. Thin out first-year canes to a 6-inch spacing between each.
* Do not spray pesticides when the weather is hot and dry. Doing so can cause leaf burning.
Pub Date: 8/10/97
