Rainforest Hydroponic System

Hydroponic gardening uses less water and fertilizer than traditional soil gardening because the water in the system is reused. General Hydroponics boasts a wide catalog of hydroponic systems and supplies, but I tried out the Rainforest 318, which was the perfect size and arrangement for my teeny rooftop herb garden. It has reconfigurable plant trays to accommodate different-sized plants. My favorite part? No potting soil to lug onto the roof!
— Becky Stern

About $250, varies by retailer
Find out where to buy at generalhydroponics.com