We love the 3-foot by 4-foot Movable Garden. It is perhaps our favorite model! With 12 square feet of gardening space, it is easy to move around, but also provides plenty of room for an awesome kitchen garden. This model is our 'middle size,' between the 3x3 and the 4x4.
The 3x4 is available with four inflatable rubber wheels (2 fixed and 2 swivel) or with legs should you choose a stationary garden. The maximum height is 36 inches. The optional polycarbonate lid can be opened to different heights; close it overnight or on a chilly day, open it wide on a hot, sunny day. The front of the box pulls up and out for easy removal of the soil.
The top of the box is built at a slope, angling the polycarbonate for optimal sunlight absorption. The interior depth of the box goes from 11 inches at the front to 14.5 inches at the rear. Filled with six inches of soil and with the lid fully closed, the plants have about 5 inches of upward growing space before they hit the lid. As your plants grow taller, it is less likely that one will need to keep the lid fully closed.
Should you fill this Mobile Garden with 6 inches of soil, plan on acquiring about 4.7 cubic feet of soil. Depending on the moisture content of top soil, 4.7 cubic feet can weigh between 356-474 pounds. Should you decide to fill the box with 9 inches of soil, plan on buying about 7.1 cubic feet of soil, which can weigh between 532-710 pounds. Although these boxes may sound very heavy to move, the four inflatable rubber wheels allow for easy mobility. Mixing peat moss, compost, or vermiculite into the top soil will significantly lessen the weight.