An irrigation control system based on soil moisture tension for potted plants was able to reduce the amount of water used to produce commercially acceptable crops. This system was adapted for use on plants growing in ground beds for cut flower production. Studies by L.R. Oki, J.H. Lieth and S. Tjosvold have shown that when the system was installed in a commercial greenhouse of Rosa hybrida L. ‘Kardinal’ plants, 26% less water was applied to the area by the grower. Productivity (stems harvested per m2) was 66% greater in the test area. Flowers harvested from the test plants were not lower in quality than those from the grower irrigated controls. The use of this irrigation control system can also reduce fertiliser usage when a liquid feed program is utilised. The irrigation control system consisted of tensiometers, modified with high flow ceramic tips and pressure transducers, an analog-digital signal converter, a computer, and custom written software. The system continuously monitors the moisture condition of the soil, initiates irrigation when the soil dries to a specific level, and turned off the water when an adequate amount was applied. ISHS Acta Horticulturae 547: III International Symposium on Rose Research and Cultivation www.acthort.org