My wife and I are new to the gardening world and are looking for advice. We're renting this property, have have a huge like 8 ft by 16 ft concrete slab in the middle of our back yard, and want to make a tiered garden box to sit on the concrete.
So, my design is sound from a getting wood and making it standpoint, but I'm trying to find out if I've planned for enough room for roots and such. Even just a link to a good website that has this info would help, as I've been pretty unsuccessful in finding anything on my own.
First, the design!
Okay, so it's an L shape, with three tiers. Short leg of the L will be 6 feet, and the long will be 8 feet. Each tier will have 1 ft of open soil, and will be 9 inches thick. We plan to plant herbs on the lowest tier, carrots, onions, spinach and bok choi on the second tier, plus maybe a couple other things if we can decide what we want, and the top tier will be 2 tomato plants on the short L, mortgage lifter, and tigerella. Then Peppers on the long L. Still working on getting all the seeds for that side, but have Bolivian Rainbow Pepper, Black Hungarian pepper, and am looking at some others.
So based on what we already have planned for the garden, and the dimensions, will we run into any problems with roots? Is 27 inches deep enough for tomatos and peppers? Is 18 inches deep enough for carrots and spinach? Is a foot wide of soil, wide enough for all of these plants?
Thanks for the info, guys! I'm ready to go buy some wood, just hoping I planned enough around.