GARDENING Q&A

Q:My husband is passionate about killing weeds in our yard. However, the more weeds he kills, the more we get. What are we doing wrong?

Answer: He might need to get into a "regular" sequence of weed control for 12 to 18 months to break their cycle. Basically, you have three main types of weeds in a lawn: perennials, summer annuals and winter annuals. Most of the weeds that were growing at the end of the summer were summer annuals. The best time to control them is when they are young and tender, in early May.

Winter annuals have just germinated and will be very visible in your lawn, although they are still small. The best time to control them is late October or early November.

Unfortunately, many people don't treat either of these weed types until they are fully grown and mature. They are harder to kill in that stage, and it's too late to break their cycle. Once weeds start to flower, they start dropping the seeds for next year's crop.

Your husband might want to begin the treatment cycle with a good broadleaf herbicide in late April for the summer annuals and late October for the winter annuals. If he has problems with crab grass, he should use a pre-emergent crab grass preventer in March.

Following this kind of management plan for 18 months should help him get ahead of weeds. However, drought summers complicate this process, because the fescue is stressed to the point that weeds can thrive.

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Answer: Many plant diseases, such as wilt, are soil-borne. And even with those that aren't, the pathogens often over-winter in mulch and debris left on the ground.

It's best to rotate tomatoes every year -- ideally, not planting them in the same place for four or five years. I know that can be hard to do in small residential gardens.

However, I wonder if the heat coming off that brick wall had something to do with the curling leaves. As the plants got large, the roots were likely to be growing up against the brick wall and would be affected by the heat absorbed by the bricks.

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Answer: It sounds as if your timing was right. Are you sure it's crab grass and not goose grass? Both are summer annuals, but many crab grass preventers will not control goose grass. Another potential problem could be the application rate. If you are applying it too lightly, it won't control as well. Also, excess irrigation will cause it to leach through the surface faster, shortening its effectiveness.

Another possibility is that people often mistake wire grass for crab grass. A crab grass preventer would provide no protection from wire grass. If you aren't positive your pest was crab grass, the local Extension office can identify it for you.

Richard Nunnally is a freelance writer and speaker as well as host of WCVE's monthly gardening show, "Virginia Home Grown." Questions can be sent to or P.O. Box 3690, Chester, VA 23831.