Large container-grown plants can be irrigated and fertilized by using nine 1/8-inch-diameter plastic tubes radiating from a central riser. Each master unit of the system is operated by a clock-controlled 3-inch valve and is capable of irrigating 720 containers simultaneously in five minutes. Four of the units now operating at a Sacramento nursery, where this study was conducted, can irrigate 2,880 containers in 20 minutes.