The Garden Doctor: Turn sandy soil into fertile oases

Healthy soil is the heart of successful, pleasurable gardening, yet Central Florida's so-called soil is so sandy it's practically fit for an hourglass. Dumping chemical fertilizers on this sand amounts to hydroponic gardening, with subsequently non-vigorous plants ravaged by bugs and fungi. That sand holds precious water only briefly, going against our efforts to conserve during our extensive drought. Of course, deep mulches are one strategy lots of us are using to transform our sand into fertile, dark soil. Another is "pit composting."

Sounds fancy, but pit composting is nothing more than digging pits of varying sizes and filling them with organic wastes that decay into compost. Each pit then serves as a highly fertile planting hole for trees, shrubs, perennials and hungry vegetable crops. Using this process requires patience, because it takes a while. Long employed in highly alkaline regions of the desert southwest like arid Arizona, pit composting is a godsend for folks gardening in alkaline coastal soils where salt is also a problem. It can help inland folks deal with poor drainage, compacted acidic sand, harmful nematodes and low fertility.

Example: For a young citrus tree or rose bush, use a garden shovel to dig a pit 3 feet wide and deep and pile the waste sand all around the hole in a big ring as you stand inside the deepening hole. Be mindful that the unfilled pit can be a stumbling hazard, especially for young children and tiny dogs, so roping or fencing the area is advisable. Then use that hole as a "landfill" for your household's wastes -- bush trimmings, organic grass clippings, kitchen scraps, used cat litter (not the scented deodorized kind but cheap clay), dog waste, spoiled citrus fruit, old firewood and fish carcasses, plus, it is hoped, a generous dollop of fresh manure of some kind. If you are fighting highly alkaline, salty seaside soil, sprinkle in 10 pounds of cottonseed meal from a feed store, 5 pounds of gypsum and 5 pounds of Ironite. If you are dealing with highly acidic inland soil, sprinkle in 10 pounds of dolomite plus broken chunks of concrete. When your pit is filled so that you have a mound 2 feet higher than the hole's rim, cover up that debris mound with the soil you dug out. You'll end up with a funny looking dome.

Be patient. You must give this a good deep watering weekly and let it mellow and compost for two to three months. It will settle until it is a slight dome, as the sand rinses down into the organic matter. Then go ahead and plant your citrus or other tree, shrub or plant. The roots will luxuriate in that humus-rich, fertile, pH-balanced underground compost-filled pit that will absorb and hold water wonderfully. In formerly water-logged, low-lying areas, that porous medium will allow for good drainage and oxygen flow for the roots.

By creating compost pits around our property year after year, we can transform our soil, recycle our wastes, conserve water and enjoy vibrantly healthy plants.

- John A. Starnes Jr., born in Key West, is an avid organic gardener and rosarian who studies, collects, cultivates and hybridizes roses for the diverse regions of Florida and Colorado. He can be reached at: THE.GARDEN-DOCTOR@worldnet.att.net.

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