Gypsum – as Soil Amendment

Gardeners are no different from other folks – they want to accomplish more work with less effort. One of the biggest jobs when gardening in north Georgia is turning hard red clay into soil that will produce healthy plants.

Occasionally, gardeners hear that adding gypsum will magically soften the soil and reduce the amount of digging that has to be done.

Read on……

In fact, gypsum does soften soil to some extent. In particular, soils that form a crust after a hard rain can benefit from top dressing with gypsum. Seedlings will be better able to emerge without the hard crust to contend with. If you notice that vegetable seedlings seem to have a hard time pushing through your soil, adding gypsum at a rate of 5 pounds per 100 square feet may help.

Gypsum also carries another benefit: the calcium it contains helps root tips to elongate and grow larger.

Chemically, gypsum is calcium sulfate; garden lime is calcium carbonate. When gypsum is spread on the soil surface, rain will dissolve it and carry it to the roots faster than lime will be transported. If you have an acid clay subsoil, gypsum may have an effect on the roots of plants within three years.

Research at the University of Georgia showed an increased yield from several crops when gypsum was plowed into the fields. If you want to experiment, spread 20 pounds of gypsum per 100 square feet and till it into the soil before planting.

So, is gypsum a miracle clay softener? Will our tillers rust from disuse?

The answer is “No” on both counts.

Copious amounts of compost or soil conditioner, mixed to a depth of 10 inches is still the only way to soften clay soil at the rooting depth.

Garden miracles still occur only in Hollywood …..and Georgia gardeners must continue their romance with their shovels.

Tags For This Article: ,