A colored water-absorbing polymer bead soaked in water (left) and original size bead (right). Photo credit: Roger Ahlbrand Flickr CC BY 2.0
Water-absorbing polymers are long chains of molecules designed to hold large amounts of water. Water-absorbing polymers have the ability to retain up to 40 times their weight in water. While they have shown to be effective in some situations, not all situations are appropriate for water-absorbing polymers.
Water-absorbing polymers have shown little effect on container plants. Also, the life of water-absorbing polymers may be reduced when exposed to high levels of salt from fertilizers.
Water-absorbing polymers can be costly. Unfortunately, their efficacy is still in question as it is unclear whether the plants can readily access water held in polymers. The development of this technology, however, could greatly advance water-wise landscaping possibilities.