Greenhouse Gear

The largest single purchase, and the one where a cheap kit costs the most. Panel thickness, frame gauge and a published snow load rating matter more than the listed square footage.

• The best cold frames, in three tiers Researched cold frame picks from a $37 tabletop unit to a twin-wall frame with adjustable lid stays, with the insulation figures, lid mechanics and venting detail that decide which survives.
• The best hoop house and tunnel kits, in three tiers Researched hoop house and low tunnel picks from $17 fiberglass hoops to a 25 by 10 ft walk-in tunnel, with covered area per dollar, wind anchoring and cover specification.
• The best walk-in greenhouse kits, in three tiers Researched walk-in greenhouse picks from a $144 starter to a 180 sq ft production house, comparing glazing, frame section, vent area, anchoring needs and heat demand.
• The best greenhouse glazing: film and panels compared Researched greenhouse glazing picks covering 6 mil poly film, twin-wall polycarbonate panels and bubble insulation, with R-values, light transmission and realistic service life.
• Best Polycarbonate Greenhouses Walk-in polycarbonate kits compared on panel thickness, frame gauge and snow load, which are the three specs that decide whether a kit survives a winter.

What keeps the crop alive through a cold night, and the controller that stops you doing it by hand at 2am.

• The best greenhouse heaters, in three tiers Researched greenhouse heater picks in electric and propane, with BTU sizing by footprint, running cost, humidity effects and the circuit limits that decide what you can install.
• The best greenhouse thermostats and controllers Researched greenhouse controller picks covering heating and cooling outlets, humidity control, differential settings and how to stage two heaters from thirty dollar parts.
• The best seedling heat mats, in three tiers Researched seedling heat mat picks with germination soil temperatures by crop, why an unregulated mat is a hazard, and how a thermostat probe placement changes the result.

Automatic openers are the highest-value low-cost item in a greenhouse, because they work on the days you are not there.

• The best automatic vent openers, in three tiers Researched wax cylinder vent opener picks for cold frames, roof vents and full greenhouses, with lifting capacity, opening temperature range and why they need no power at all.
• The best greenhouse exhaust fans, in three tiers Researched greenhouse exhaust fan picks with CFM sizing by house volume, shutter versus inline designs, intake area requirements and the corrections for elevation and shade.
• The best greenhouse circulation fans Researched circulation fan picks for moving air inside a closed greenhouse, with the airflow rates that control fungal disease, oscillation, and why this is not an exhaust fan.
• The best evaporative coolers for greenhouses Researched evaporative cooler picks for greenhouses, with the humidity limits that decide whether they work at all, water use, and why shade and extraction come first.
• The best greenhouse shade cloth, by percentage and crop Researched shade cloth picks with the correct shade percentage for seedlings, vegetables, orchids and ornamentals, plus why exterior fitting matters more than the fabric.

Hand watering is fine until it is a hundred degrees and you are away for a weekend.

• The best greenhouse irrigation kits, in three tiers Researched greenhouse drip irrigation picks with daily water demand by season, emitter selection, zoning, and why drip beats overhead watering under cover.
• The best greenhouse misting systems Researched misting system picks for propagation humidity and evaporative cooling, with nozzle types, pressure requirements and why misting a humid house is the wrong move.

Benching, propagation and lighting. The equipment that decides how much of the space you can actually use.

• The best grow lights for seed starting, in three tiers Researched grow light picks for vegetable and flower seedlings, with the PPFD each delivers at working distance, DLI targets, photoperiod and why hanging height beats wattage.
• The best seed starting trays and propagation supplies Researched seed starting picks covering 1020 trays, humidity domes, soil blockers, starting media and the capillary matting that removes damping off risk.
• The best greenhouse thermometers and hygrometers Researched greenhouse measurement picks covering max-min thermometers, logging hygrometers, soil thermometers and the three numbers that actually drive decisions.
• The best greenhouse benches and shelving Researched greenhouse benching picks with the working heights, mesh versus solid tops, load ratings and layout arithmetic that decides how much of a house is usable.

Everything else worth a considered opinion.

• The best row covers and frost blankets, by weight Researched row cover picks with the degrees of frost protection and light transmission each fabric weight gives, plus insect mesh, cloches and how to secure covers in wind.

One structure at a time, priced per square foot. The number that decides most of these is not the footprint, it is whether the maker publishes a wind and snow rating you can check against your own site.

• Palram Canopia Oasis Hex 7 x 8 review Over 90 percent light transmission and a 55 mph rating, at about $41 per square foot. The shape is the reason to buy it and the reason not to.
• Palram Canopia EcoGrow 6 x 8 review 6 mm twin-wall walls and a resin frame with no thermal bridge. The kit to buy when the house has to hold heat through a real winter.
• Palram Canopia Hybrid 6 x 10 review Clear walls, twin-wall roof, 60 sq ft at about $12 per square foot. The best value branded kit here, and it ships short on venting.
• Palram Canopia Mythos 6 x 6 review 36 sq ft of 4 mm twin-wall for plots that cannot take a longer footprint. Small volume means it swings hard in both directions.
• Broivira 8 x 12 greenhouse review 96 sq ft at roughly $6 per square foot, with no published panel thickness, wind rating or snow load figure.
• Glanzend 6 x 8 greenhouse review 8 mm panels and a galvanized base for about $144, which is the cheapest route into hard glazing and comes with no load rating.
• U-MAX 6 x 8 wood greenhouse review Thirteen shelves included and a timber frame that takes a screw anywhere, in exchange for treating it every year or two.
• Quictent 25 x 10 tunnel review 250 sq ft of covered ground at about $1.14 per square foot, on a cover you should treat as a consumable.
• JUWEL Bio Protect 2000 review 8 mm thermal panels and netted lockable windows in a bed system, for overwintering crops rather than hardening off.
• Backyard Discovery Aggie cold frame review A wax hinge that opens the lid above 70 F with no power, which fixes the way cold frames actually kill crops.

Size the heater from a heat loss figure rather than from the shelf. Insulating and sealing the structure changes the required output by more than the gap between any two of these units.

• Ashley Hearth direct-vent propane review 11,000 BTU of sealed combustion for a greenhouse with no power, installed and commissioned by a qualified gas fitter.
• Bio Green Phoenix 2.8 kW review 9,553 BTU across two switchable stages in a stainless body, on a 240 V circuit most domestic greenhouses do not have.
• Bio Green Palma 1500 W review 5,100 BTU, IPX4 splash protection and a digital thermostat on a standard outlet. The right size for most domestic houses.
• Dr. Heater DR218 review Infrared that warms benches and soil rather than the air that leaks out, bundled with an external heating and cooling controller.

Shade first, then venting, then anything powered. Heat you keep out of the structure never has to be extracted from it, and that is the order these should be bought in.

• 90 percent shade cloth review 800 sq ft of grommeted mesh at a density that suits cuttings and starves tomatoes. Density is a crop decision, not a heat one.
• iPower 14 inch shutter fan review 1,000 CFM at 70 W with a controller adjustable from 50 F to 120 F, and the low-level air inlet it cannot work without.
• Hessaire DC18 evaporative cooler review 900 CFM that cools properly in dry air and adds humidity you do not want in damp air.
• Yokekon 30 L humidifier review 4,000 mL per hour on a humidistat, for propagation areas only. Most greenhouse humidity problems run the other way.
• MistKing Starter misting system review A pump and timer that keeps unrooted cuttings turgid. It is not irrigation and it will not water pots while you are away.
• FREELICHT 5-tier grow light stand review Five tiers and four 30 W bars in about 3 sq ft of floor, with no published PPFD figure for either.