Patti: Hi. I’m Patti Moreno, The Garden Girl.

Mel: And I’m Mel Bartholomew the Square Foot Gardening Guy.

Patti: You know, one of—and this has to be on the top of the list of the most frequently asked question, is six inches really deep enough to grow your vegetable garden?

Mel: Right. That is a good question. And it’s hard for people to understand when they’ve been used to being told they have to dig real deep. We have to turn the soil or we have to constantly be in route of telling that. In fact, when I give a lecture or a symposium, one of the trick questions is, how do you grow 12-inch long carrots in six inches of soil. And of course it’s very difficult, but we have a solution for that. Let me answer the question at the very beginning. I was looking for a better way to garden, obviously square foot gardening is much easier, simpler, no tools, we do since the size of the garden is only 20%. It saves water, it saves seeds and all of those things, and you take better care of your garden. It’s funny that you still have to dig up the existing gravel and mix it with some really good stuff.

And I went to some commercial green house. And when I walked in, there were these benches, and on the benches were boxes and the boxes were made out of wood and they are only six inches deep, and they are filled with a soil mix. And I asked them, “What kind of soil is there?” “That’s perfect soil.” Well, I got thinking, Mel’s Mix? The formula? 1/3 peat moss, 1/3 vermiculite and 1/3 compost is a perfect mix. All those are natural. They hold water. They also drain well and they are growing all these crops; peppers, eggplant, tomatoes, flowers, everything, not in individual containers but on the bench in the box. And the tomatoes by the way had strings attached and they go right up to the ceiling. They grow vertically. Well I though, if they could do that in a commercial greenhouse, why can’t that hold concept beyond the ground and be done in a square foot garden?

So I experimented. And I put the boxes on the ground, did not dig up the existing ground, just put them right on top, put down the weed cloth so the weeds wouldn’t come up through and into the soil mix. And now of course, the experts told me I can’t do it. You need 12 inches or you need 18 inches and roots go real far. And I said, “Well, why are they going real far or real deep?” Well, they are looking for moisture and they are looking for nutrients. Well, wait a minute, Mel’s Mix has ten times the amount of nutrients because we are using compost as 1/3 of the mix. All the ingredients are natural and organic, the peat moss, the vermiculite and the compost, but it holds a lot of water. The roots stayed right there because it had al the nutrients and all the moisture it needed. And I was like, “Well, why would we go to 12 inches if 6 inches is not.” 12 inches costs twice as much and takes twice as much work. Let’s stick with 6 inches.

So I did it in all of the country where I put in different display gardens, it worked! Six inches worked. Now, the experts still came back and said, “Well yeah. But…” they love to say “Yeah, but…” What about tomatoes? What about corn? They share roots way out. And again, I asked them what they are looking for. And I found out that even one tomato plant in one square foot on six inches deep will grow just fine. And now, we’ve even grown things like berry bushes, strawberries, we’ve put in asparagus, all kinds of things that you would normally would not expect but still grows in six inches. Which goes back to, it’s a perfect soil mix.

Patti: Well, thank you so much for answering that burning question. It’s true. And if you don’t believe it, try it yourself. I’m Patti Moreno the Garden Girl and definitely check out more answers from Mel as part of our frequently asked questions.