Capillary mat is an absorbent fabric available at greenhouse supply companies. Capillary mat subirrigation has been used in the greenhouse industry for more than 40 years. The traditional system uses periodic applications of water to saturate the mat. The growing medium in containers in contact with the mat will absorb water through the holes in the bottom of the pots and subsequently irrigate the plants in the pots. The RAFT system makes capillary mat irrigation automatic because the edges of the mat are draped into the water which allows the capillary mat to wick water to the containers, growing media and plants grown on the surface.
Commercial growing medium, soilless mix, potting soil, potting compost, etc. are names for various materials used to grow plants in containers. The concept started at Cornell University with the "peat-lite" mix composed of 50% sphagnum peat moss and 50% vermiculite plus fertilizer additives for initial plant growth. Growing media and potting soils now are manufactured by many companies in many formulations. They are composed primarily of sphagnum peat moss (Canadian peat or red peat) and/or composted bark. Additionally, vermiculite, perlite, black peat (Michigan or Indiana peat), processed bark, rice hull, peanut hulls, processed clays, polystyrene beads, rockwool and other materials may be added. Commercial grade media (available from greenhouse and nursery supply companies) will perform better in containers using the RAFT system than consumer grade media (available from discount stores, supermarkets, etc.).
The "Float System" is a simple subirrigation system for plants. The system is based on the Todd Trays (polystyrene trays developed by George Todd) and subsequently used and sold by Speedling Inc. These trays float on a tank or bed of water even when filled with a growing medium and plants. The system is usually successful for tobacco transplants and may be successful for vegetable transplants or bedding plants. For this system to be successful, the plant must be able to tolerate relatively saturated growing conditions because the tray partially sinks into the water. This condition is aggravated when growing media is settled or packed into the individual cells of the tray. The saturated conditions make an environment well suited to root, stem and foliar diseases that may severely damage the crop. Disease problems are accentuated when contaminated trays are reused. The polystyrene composition of the tray and its' degradation in light and where roots can damage it, make the tray difficult to sterilize.
Square Foot Gardening is a home garden concept explained by Mel Bartholomew in his classic 1981 book "Square Foot Gardening" published by the Rodale Press, Emmaus PA. The concept revolves around the use of every square foot of space in a residential garden by rotating crops through the garden as the season progresses. So the cool spring crops of spring are replaced by warm season crops in the summer and these are replaced by cool season crops in the fall or by green manure crops to replenish the soil.
Cooperative Extension Service --- University of Kentucky
