Water Retention Through Modern Science

Planting is always a risky business. Dry weather, wet weather, and infestation by insects and disease threaten young plants. Soil content, especially airspace, water and nutrient supply are three of the most critical factors in plant growth.

But now the odds for plant survival may be improving dramatically. Modern chemists have given us a super-absorbent gel that can hold water in the soil, making it available to plant roots during dry periods.

These gels are a long molecule called a polymer. They can be starch or synthetic-based, but because the starch-based gels are unstable in the ground, most used in landscaping are of the synthetic variety.

In rapid draining soil or containers, gels are used when planting. They are mixed with soil and backfill throughout the planting site. After the plant is placed and then watered, the gels become completely saturated, usually within about an hour, according to Terry A. Tatter, Ph.D., University of Massachusetts, as reported in the March 1990 issue of "Landscape Management." The synthetic gels don't collapse from soil weight. According to test results thus far, they last about two years and then degrade.

Although research is still being done, the gels seem to prevent damage to plants that can occur during droughts by holding water in the soil for root systems to absorb as needed.

Planting is a critical time for plants. Polymers allow the new addition to your landscape to have a ready water supply available through the recovery period following planting.

Thus far, the only real problem associated with gel use is simply a case of "too much." In some instances, so much was used that plants were shifted out of position by the expansion of the polymers underground. In addition, many of the polymers worked their way to the surface, theoretically from expanding and rubbing against one another.

The other potential hazard is that the polymers will hold too much water but no evidence exists yet to prove or disprove that.

Right now, use of this substance is emphasized in spring plantings to help a new plant get established through a first dry summer. Research continues, so stay tuned for further developments.