The square foot gardening system boasts of saving 90% of traditional water usage. Hearing this leads folks to thinking they don’t have to water their gardens very much. That’s really not the case. In fact, this thinking leads to the 2nd most frequent cause of failure in the square foot gardening system.
Here’s what the thinking should be: lets say your current garden space is a 20’X 20′(400 square feet)piece of land. If you were to change that garden over to a square foot garden, you would only use 20% of that space, or 80 square feet-roughly a 9’X 9′ patch of ground. Whereas before you would be watering 400 square feet of garden land, you now are only watering 80 feet of land-an 80% reduction. If that’s true, where does the 90% reduction number come from? Easy-course vermiculite. This material is excellent at retaining water and accounts for the additional 10% reduction. Of course in the SFG system, we’re talking about using course vermiculite. While it’s important to get course vermiculite in your soil, it can sometimes be a challenge to find. Vermiculite comes in three grades: course, medium, and fine. If you can’t find course, get the medium. If you can’t find the medium, get the fine. Whatever you do get vermiculite in your soil. The finer grades don’t hold as much water but it’s better than no vermiculite at all.
Once your gardens have been thoroughly watered in it’s important to keep the growing medium moist-just like any other garden. One of the ways I can tell I’ve got enough water on my garden is a simple visual check. I know that if my soil is light colored it doesn’t have enough water. This picture is an example of how dark my growing medium is-all the time. If I come out to discover it’s a light brown color, I know it’s gotten dry and it’s time to lay more water on it. While you can certainly stick your finger into the soil to get an idea of how dry/moist your soil might be, I prefer the visual check. It’s been the best barometer for me over the past 15 years.
Make sure you’ve got enough water on your gardens. It’s difficult to over-water these gardens with the addition of vermiculite in your soil. Any excessive water will drain out the bottom