is soil absorbent
Adding hydrogels to potting soil can reduce water needs of plants. Water-absorbent materials, called hydrogels or hydrophilic polymers, are made from crystallike polymers that can help reserve moisture in planters when added to the potting soil mix.eplace water-absorbent materials periodically, since their effect on potting soil is not permanent. Through natural decomposition, the hydrogelsâ ability to absorb water is depleted within about five years.