Sub-irrigated planter From Wikipedia, the free encyclopedia Sub-Irrigated Planter Sub-irrigated planter (SIP) is a generic name for a special type of planting box used in container gardening and commercial landscaping. A SIP is any method of watering plants where the water is introduced from the bottom, allowing the water to soak upwards to the plant through capillary action. It is possible to automate the watering and thus SIPs are popular with professional landscapers in buildings or urban settings. SIPs are available as products, under brand names such as Planter Technology (commercial) and EarthBox (consumer), Ollie Plant Sipper(consumer), The Refuge Garden (www.urbanrefugegardening.com) (consumer/commercial) or as do-it-yourselfprojects made from plastic buckets and boxes. Would love to hear about your experiments, projects, failures and successes.