Avoid mess by staying on top of weeds

KENNEWICK -- This is the time of year when gardeners like to sit back, relax and enjoy the fruits of their labor.

That is just what I do for several minutes every evening. What a pleasure it is to hear the gentle sound of the water from the fountain in my little water garden and to smell the delicate fragrance of the wave petunias. However, a gardener seldom rests for long, there's always something needing attention in the garden.

Nasty weeds start growing with a vengeance in hot weather and it's easy for them to get ahead of you. They compete with garden plants for water, nutrients, space, and sun. There's always a weed somewhere that should be rogued out.

One reason weeds are so troublesome is that they produce lots of seeds that can stay around for a long time.

One common purslane plant can produce 1.8 million seeds. These purslane seeds can persist in the soil for 20 to 25 years. One plant of puncture vine, an infamous and dastardly weed in our region, can produce 100,000 seeds that will remain viable for three years. By keeping up with the weeds in the garden and landscape, you can help decrease the problems you'll have with them now and in the future.

I don't know about you, but I don't like the task of continually pulling weeds. To help avoid it as much as possible, all my garden beds have a 4-inch layer of small bark mulch. Mulches help with weed management by preventing light from reaching germinating weeds. Without light they can't grow. In addition, organic mulches help conserve soil moisture and keep the soil cooler. They also add organic matter to the soil as they decay.

To effectively discourage weed growth, an organic mulch must be thick enough to exclude light.

Bark and pine needle mulches should applied in layers 3 to 4 inches thick; grass clippings and shredded leaves 2 to 3 inches thick; newspapers 6 to 7 sheets thick; and bagged sterilized steer manure 1 to 2 inches thick.

Compost can be used in a 1 to 3 inch thick layer, but if the compost did not go through adequate heating you may be introducing weed seeds into your garden, not discouraging them.

Because organic mulches decompose, they will need to be replaced with time.

Weeds aren't the only plants that produce seeds.

For annual flowers, seed production is their means of surviving from year to year. Once they flower, the plants' energy is directed towards producing seeds and flowering may slow or stop. That's why veggies (such as zucchini, summer squash, and beans) should be harvested on a timely basis and why many flowering plants should be deadheaded regularly.

The term "deadheading" sounds so sinister, but it simply means removing spent flowers from your flowering plants. It encourages many flowering plants to keep blooming, plus the garden looks neat and tidy.

All you need is a little pair of garden snips. Just clip the flowers off at the first set of leaves beneath the flower.

Many newer annual flower cultivars, such as the Wave petunias are "self-deadheading" with the shriveled blossoms dropping off the plant automatically.

* Marianne C. Ophardt is a horticulturist for the Washington State University Benton County Extension Office.