A Grow Bed is the most efficient garden area you'll ever tend, with black plastic sides that absorb heat to warm soil early in the season, then help retain moisture all summer long. These three-sided extension kits double the growing space of our poplar grow beds by creating a raised bed that is the same width but twice as long. Add these extension kits to our Grow Beds to double the space Space-intensive gardening produces high yields Ideal for small space kitchen gardens Extends the growing season Choice of 2 sizes Earth-friendly, 100% recycled plastic Each kit contains 3 sides and a hardware pack Mini Grow Bed Extension Kit holds 97 quarts of soil 38-3/4" L x 20-3/4" W x 10-1/4" H --> Easy assembly; requires drill Gardener's Supply Exclusive