Volume 14, Issue 45 ~ November 9 - November 15, 2006

The Bay Gardener

By Dr. Frank Gouin

Keep Your Soil Alive

Welcome microorganisms into your garden

Good garden soil is rich in organic matter and bursting with active microorganisms digesting organic matter. Such biologically active soil is productive because organic matter releases nutrients as it decomposes. Microorganisms that eat organic matter prevent disease-causing organisms from attacking your plants. Soils where all plant and plant residues are removed soon become compacted, unable to support plant growth because the soil has few nutrients, absorbs water poorly and cannot retain the water it does absorb.

The simplest and most efficient way to keep your soil alive and well is to keep plants growing in the garden throughout the year. If you grow a flower garden, consider planting annuals and perennials in close proximity to each other. The tops of perennials may die back to the ground during the fall and winter months, but perennial roots stay active throughout the year, as long as soil temperatures keep above freezing.

For an annuals-only garden in the fall plant winter annuals such as pansies, sweet Williams, ornamental cabbage or kale. Vegetable gardeners should grow fall crops such as turnips, kale, cabbage, broccoli or collard greens.

If you don’t want to plant winter annuals or fall vegetable crops, try planting a cover crop of winter rye grass. Winter rye grows a lush green carpet of grass, absorbing nutrients not utilized by the previous plants, protecting ground waters and preventing your soil from being washed away by heavy rains. Winter rye grass is the best scavenger crop available. It grows roots deep in the soil, and the roots and stems that grow during the winter and early spring equal nearly one inch of peat moss per year. The root system of winter rye grass, however, is better than peat moss because lignins-rich rye grass roots decompose more slowly than peat moss, which is nearly void of plant nutrients.

Forcing Wisteria to Bloom

Q We maintain a hotel in D.C. that has Wisteria sinensis that has not bloomed in over 15 years. I can become a hero in the eyes of the GM if I can get this plant to bloom. Any suggestions you can make on how I can make this happen? By the way it has four- to eight-foot trunks and is upwards of 60 feet long in places.

—Dave Lindoerfer, Washington, D.C.

A It is very easy to force a stubborn wisteria to bloom. Next spring after the plant has developed fully mature leaves, take a hacksaw and completely girdle the stump near the ground level. Make certain that you cut through the bark and well into the cambium region, and make certain that you go completely around the circumference of the trunk. You won't kill the plant.

What you are doing is stopping the metabolites produced by the leaves from entering the root system. This will back the metabolites up into the stems and branches, forcing the plant to set flower buds if it wishes to survive. The wounds that you made will heal by mid summer. Within two years, you will see the plant blooming. You need only do this procedure once. After it has started to bloom it will continue — unless you over-fertilize it. Don't fertilize it from now on.

Ask Dr. Gouin your questions at frgouin@erols.com. All questions will appear in Bay Weekly. Please include your name and address.

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