When and why to deadhead

THE BALTIMORE SUN

What is the purpose of deadheading flowers, and should all flowers be deadheaded?

Plant seeds are produced in the ovaries of flowers. When the flowers are removed by deadheading, the plant stops producing seeds and instead uses that energy to produce more flowers. So the goal of deadheading is to encourage plants to produce more flowers.

It works on a number of plants, especially those perennial plants that have long bloom periods in the summer and fall. Some of the plants that benefit from deadheading are coneflowers, blanket flowers, black-eyed Susans and garden mums.

Other plants do not seem to benefit from deadheading. For example, most daylilies produce only a certain number of flower buds each summer and will not produce more when deadheaded. The exception might be a few of the long summer blooming daylilies like 'Stella d'Oro.' Also, some plants produce an abundance of flowers all summer without deadheading, so it is really unnecessary. An examples of this is impatiens, which sheds its old flowers readily and will continue to produce more flowers until frost.

We recently noticed a mass of what looked like a fungus growing on our mulch, but it is dry and crusty. Is this a fungus, is it dangerous and how should we treat it?

The growth you are talking about is actually not a fungus but a slime mold. It is often brown, yellow or orange in color, and many people describe it as looking like dog vomit. During cool, wet periods like those we have had this summer, the mold grows from spores in the mulch.

Slime mold is not dangerous and will not harm you or your plants. I generally recommend leaving it be, but you can get rid of it temporarily by raking it with a stiff metal rake or by hosing it down with a sharp stream of water.

Checklist

1. Japanese beetles are active again and devouring the leaves of plants. These shiny copper-green insects can often be controlled by hand picking.

2. Visit your local garden centers now for great deals on end-of-the-season items such as watering equipment and outdoor furniture.

3. Has crabgrass invaded your lawn? By mowing it regularly, you can prevent the crabgrass from forming seed heads. If the crabgrass goes to seed, it will return again next year.

Dennis Bishop is an urban horticulture educator for the Baltimore office of the Maryland Cooperative Extension Services. If you have a gardening or pest problem, you can call the Home and Garden Information Center hot line (Monday through Friday, 8 a.m. to 1 p.m.) at 800-342-2507. You can also e-mail questions, order publications and diagnose plant problems by visiting the Web site www.hgic. umd.edu.

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