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Journal American Rhododendron Society

Current Editor:
Dr. Glen Jamieson ars.editor@gmail.com


Volume 39, Number 4
Fall 1985

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A Cool Gardening Tip From San Francisco
Ralph J. Zingaro, Oyster Bay, New York

        Fall is a wonderful time of year. The air is cool and crisp and nature reaches a climax of bright yellows, reds, oranges and scarlets. Fall is fruitful too, with plenty of fresh apples for the eating. What could be a better time, with the cool breezes circling, to nourish and strengthen your plants for next spring? In fact, one thorough mineral application this fall will provide your plants with enough nutrition to last them until the next fall season.
        The science behind this is really quite simple. Nitrogen is an element that provides a plant with the green stuff it mostly consists of, namely leaves. Phosphorous, on the other hand, concentrates on the development of a part of plants that one cannot see - the roots. The latter also stimulates flowering. Potassium is responsible for those strong upright stems we all try to get on our long stem red roses.
        In the spring and early summer months a plant's main goal is to break bud and grow leaves naturally. Conversely, during the late summer and fall, plants begin to slow down their leafy growth and begin to concentrate on root growth. Subsequently, all the stem and leaf growth begins to "harden off." Last fall our plants had a problem. The weather remained relatively mild well into November. This unusually mild weather prevented the plant tissue from hardening sufficiently before the real serious cold weather set in. So, when the weather turned sharply colder around Christmas time, many plants suffered winter damage.
        Since San Francisco has a Mediterranean climate the weather is not as cold as ours. However, an occasional frost does occur, and high winds which cause drying or desiccation are a constant threat. Gardeners in this area have adopted a very useful and ecological technique for nourishing and protecting their plants from those incessant winds and occasional frosts. At least once per year, preferably in the fall, an application of 0-20-20, 0-10-10, or 2-20-10-10(S) is made. These formulations contain very little nitrogen (usually less than 3% by wt.). The emphasis is placed on the phosphorous, potassium and more importantly sulfur. The importance of sulfur is that it will green up a plant as well as nitrogen without forcing late leaf growth. Another bonus is that it will not leach into the ground water like nitrogen does. This is especially important on Long Island where excessive nitrogen leachate is endangering our water supply. The phosphorous and potassium both harden up the growth, thus making the plant naturally resistant to winds and cold. So take a tip from those innovative folks from the Bay area and use 2-20-10 now.


Volume 39, Number 4
Fall 1985

DLA Ejournal Home | JARS Home | Table of Contents for this issue | Search JARS and other ejournals