They have built-in water reservoirs that keep the soil moist long after other pots have dried out. As an added bonus, Bemis-grown plants outperform plants grown in ordinary containers. The ventilated inner floor of the pot provides good air circulation, so the roots get plenty of oxygen. Made of resilient, ultraviolet-stabilized plastic, the pots are available in classic terra cotta, dark green and handsome earth tones. The Bemis containers come in a variety of sizes.
Large pots hold moisture longer, so bigger is better when containers are placed in full sunlight.
I found the best selection locally at Frank's Five Seasons on Hall Road in Clinton Township. Made of recycled tire rubber and looking like huge brown cookies, these thick disks act as a permanent mulch that helps protect newly planted trees from slasher tools such as lawn mowers and string trimmers by eliminating the need for trimming around the base of the tree. Homeowners who consider bark mulches messy will find these rings a tidy alternative. The rings are heavy and thick enough to stay put, and dense enough to block the growth of weeds and grass. Environmental tests on the recycled rubber material, which allows moisture and air to pass through it, shows it to be nontoxic.