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Tuesday - August 12, 2008

From: Washington, DC
Region: Mid-Atlantic
Topic: Watering
Title: Self-watering planters
Answered by: Barbara Medford


I'm a big proponent of the EarthBox (tm) phenomenon - that is, so-called "self-watering" or sub-irrigation planters where a separate but connected reservoir underneath the soil in the planter is filled and the plant draws its moisture upward from there. You don't water the plant, you water the reservoir. My question is this - many websites seem to suggest that a plant cannot be overwatered through this method because the plant "takes what it needs and that's it." It seems more realistic to me that, unless the planter is in full sun for the majority of the day, the plant will not use that much water, the soil will become overly wet, and the roots will rot. Shouldn't an indoor sub-irrigated planter be allowed to dry out somewhat before being replenished? Thanks in advance!


Since we had never even heard of this product, we went to some of the websites on it. We couldn't pass any kind of judgment on something we had never personally used. However, just from the instructions, it seems to be an awfully complicated way to grow a plant. Our impression was that it was mostly being utilized as a means to produce vegetables. The Lady Bird Johnson Wildflower Center is committed to the use of plants native to North America and to the area in which they are being grown. Very few vegetables are native to North America and those that are have been so extensively hybridized that they really don't fall into our area of expertise. It seems a number of the users are from the U.K., where perhaps they don't have enough sunlight or warm weather to grow things in the dirt.

To attempt to answer your question about whether the roots are safe from drowning in the planter, we would imagine they are. Probably the system works just fine; the company would have difficulty continuing to sell them if the plants in them croaked. Really, our own problem with the concept is that it kind of takes the fun out of gardening. To many gardeners, present company included, gardening is something you DO, not something you get produce from. It seems like a lot of trouble and expense to grow things that can be purchased at the grocery store. Pottering around among the plants, deadheading, sprinkling, pulling up the odd weed, and having a chat with the recalcitrant members of your plant family would all be replaced by plastic, fertilizer strips, netting and screens. It is not the policy of Mr. Smarty Plants to weigh in for or against commercial products; decisions on this should be left to the individual.

We did find some websites on the product that you may want to look at; mostly they are from the company itself, but one, Dave's Garden forum on The Scoop on Earth Box, has some comments from people who have used them. One from the company is Welcome to Earth Box.


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