Q. I have three euonymus bushes that have always been healthy. This year, however, strange growths that resemble little heads of cauliflower are growing on some of the stems. The growths darken with time but have not seemed to hurt the plants. Is this a disease? Should I be concerned?
A. The growths are known as crown gall disease and are caused by a very common bacterium that lives in soil. The bacterium enters wounds on plant stems. Although unsightly, the galls rarely cause problems. Prune out the affected stems and continue to keep your shrubs in good health.
Q. I want to plant some trees in my yard this fall. Should I make a hole just big enough for the root ball and let the grass grow right up to the trunks or should I dig up a large section of grass and keep mulch around the trunks?
A. The latter approach is much more sensible. Each tree should have at least a 10 foot diameter "grass-free" zone. You might want to consider grouping your trees into one large planting island. The first approach you mentioned is much less desirable. Grass will compete with the new trees and check their growth. You are also more likely to injure your trees with a lawnmower or weed eater. Keep the weeds down with 1-2 inches of mulch. If the soil is compacted or is heavy in clay, mix some compost into the entire planting area, and not just in the planting hole.
Q. I grew some heirloom tomatoes this year and really liked them. Can you save seeds from unripe tomatoes? How should I store them for planting next year?
A. They do not have to be ripe. You can successfully save tomato seeds from any of your tomatoes that show the slightest color change to pink or red. Scoop out the seeds from large, solid specimens and place them in a container with a cup of water. Set the container in a garage or porch area for five to seven days. Pour the scum off the top and dump the seeds into a strainer. Wash the seeds thoroughly with water and lay them out on paper plates to dry for seven to 10 days. Then store them in a labeled glass container in a cool, dry location.
THIS WEEK'S CHECKLIST
1. Dig up extra chive, parsley, garlic and thyme. Pot them up and bring them indoors for the winter.
2. Pick pears when the background fruit color turns from a dull green to a greenish yellow. The breathing pores on the fruit surface, called lenticels, will turn from white to brown. Keep fruits stored in a refrigerator or other cool location. Bring them to room temperature to finish the ripening process.
3. Leave large wasp and hornet nests alone. Wasp activity will cease after the first fall frost.
Backyard Q&A; is by Jon Traunfeld, regional specialist for the Home and Garden Information Center, Maryland Cooperative Extension Services of the University of Maryland. For additional 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 www.agnr.umd. edu / users / hgic.