Earlier in the Spring a friend of mine suggested I try out Sub-Irrigated Planters, also known as “SIPS” or sometimes “Self-Irrigating Planters.” These types of planters can be purchased or improvised, and employ a reservoir of water that allows the plants to wick the proper amount as they grow. My SIPS are mostly constructed from materials I had around the house or purchased from The Dollar Store, while many other effective designs can be found online. I am amazed at how the plants thrive in these planters, and at how little space they require.
This Plant Spa was purchased at The Dollar Store for less than $5 as part of my experiment. Please note the reservoir opening at the bottom.
I improvised two large SIPS by using standard hole-in-the-bottom planters. The reservoir is made from a plastic colander and an inexpensive plastic dish tub (see below.) The colander and tub prevent over-watering and root-rot by allowing excess water to overflow out of the planter. The colander also allows for aeration as the plants “wick” the required moisture.
Lastly, I improvised a “colander” out of a juice bottle so that I could turn an ordinary clay planter in to a small SIP. A hack saw was used to saw the bottle in half.
Next I used the awl of my Swiss Army knife to punch holes in the plastic, giving it the look of a colander.
The clay SIP ended up looking like this:
I stirred a dash of lime into my fertilized potting mix, then added tomato and pepper plants. During the first week, I watered the plants from the top, ensuring that the reservoir below was always full. Since then I only add water to the reservoir as the plants are clearly wicking the perfect amount.
After six weeks of growth, I am thrilled with the size of my plants!
I am so thrilled with the results that I cannot wait to try more SIP designs next year!
By John A. Heatherly
my son gave me a cherry tomato plant in a decent size sub-irrigated planter. He made several from fairly inexpensive items found at Home Depot. Along with the help of his worm tea fertilizer my plant is growing an average of 2″ a day. It’s bushing out nicely and I’m hoping to get a good steady crop, including cuttings for clone plants, from this one plant. I recommend a worm compost with some red wigglers and a way to collect the ‘tea’ for any gardener.
Sub-irrigation makes a superior container pot, and container pots allow you to move the plant. So far I’ve had to move mine to protect it from hail and severe winds, then back to catch the rays.
How do you control for mosquitos breeding in the stagnant water at the base of each pot? We had an outbreak of West Nile virus last summer in the area where I live and the Health Depart warned the public not to leave standing water in flower pots, wading pools, etc..
mine has a watering tube running up the inside wall of the pot, which could be plugged to keep mosquitoes out. There is a very small drain hole in the side of the pot at the water line for overflow. So there is no access to standing water. The design can be found online when you search for sub-irrigated pots.
Mosquitos are definitely an issue with this type of design. There are a number of SIP plans online that are more “sealed” that I plan to try out next. Great point.
Love this article! I’ve used SIPS before but never even thought about making my own. Sounds like a great project for Girl Scouts!
I agree that mosquitoes are an issue so I’m going to modify this design by taking a piece of nylon screening and putting it over the reservoir before I put the pot in it. If I drape it to the ground and put a rock on each corner it should be easy to lift to check the water level but still keep mosquitoes out. I don’t believe it will interfere with the water-wicking process but I’ll let you know.