The advantages of gardening in grow boxes – less weeding, more control over water and fertilizer, and ease of tending and harvesting – are well documented. This set of stacking corners gives you everything you need, except the lumber, to build a raised-bed grow box.Although you can make boxes of any height (in multiples of 7 1/2"), a three-tier box gives you a bed deep enough to be both effective and convenient. Tall people might want four tiers for best height. Nominal 1" × 8" wide material…