Greenhouse Kits for the Backyard

Two kinds of greenhouse in one collection

The greenhouse kits here split into two groups, and the cover material is what separates them.

PE cover greenhouses use a heavy woven polyethylene sheet over a powder-coated steel frame. The 140 GSM cover lets through around 85% of sunlight, goes up in an afternoon, and comes down again at the end of the season if you want it to. They're the budget-friendly way to start seedlings early or keep tomatoes going into fall.

Polycarbonate greenhouses use rigid 4mm twin-wall panels on an aluminum or steel frame. They hold heat better, stand up to wind and light snow, and are built to stay up year-round. Expect a full day or two of assembly.

Choosing a size

Footprints run from compact 7 x 4.7 ft and 8.3 x 6.2 ft models up to walk-in houses of 8 x 12, 10 x 14 and 10 x 32 ft.

A useful rule: you lose about a third of the floor to the path down the middle, so pick a size based on the bench or bed space you actually need.

If you only want to raise seedlings for the vegetable garden, a 6 to 8 ft model is plenty. For growing in the greenhouse itself, or for overwintering citrus and potted plants, go 12 ft or longer. Allow 3 ft of clearance around the outside for assembly and maintenance.

Lean-to or freestanding

A lean-to greenhouse attaches along one long side to a house wall, garage or fence. It picks up heat from that wall at night and needs less ground, which makes it a good fit for narrow side yards. A south-facing wall is ideal.

Freestanding and walk-in models get light from every side and give the best airflow. They need an open, level spot away from overhanging trees.

Ventilation and anchoring

Heat builds fast on a sunny day, even in spring. The PE models have roll-up side windows with mesh netting, so you get cross breezes without letting insects in. The polycarbonate houses use roof vents and sliding or swing doors. Open them once the inside passes about 80°F.

Every kit needs anchoring. On soil, use ground stakes or set the base into a shallow trench. On a patio or deck, bolt it to the surface or weigh the base down. An unanchored greenhouse can lift in a strong gust.

Setting up inside

Tiered shelving gets the most out of a small footprint, and a 4-tier plant stand with a zippered PVC cover is in the range for balconies and decks. In larger houses, keep tall crops on the north side so they don't shade everything else.

If the greenhouse sits near where you entertain, our outdoor living pieces and fire pit grills can turn that corner of the yard into somewhere you actually spend time. For permanent green on a patio with no upkeep at all, there are artificial plants too.