Put a greenhouse in the wrong corner of the yard and you pay for it every season: leggy seedlings reaching for light, a structure that ices over on calm nights, and a 40-minute round trip with a watering can because you sited it too far from the spigot. The spot you pick matters more than the brand you buy, and once the foundation is down, moving it is a weekend you will not get back.
This guide covers where to put a greenhouse, the practical siting factors that decide whether it thrives or sulks. For which way it should face, see our companion guide on greenhouse orientation.
TL;DR: The best location for a greenhouse gets at least 6 hours of direct sun a day, sits on level, well-drained ground, and stays clear of shade and frost pockets. Keep deciduous trees 25+ ft away, position above the base of any slope, shelter it from wind, and place it within reach of power and water.
A good greenhouse site is sunny, level, well-drained, and convenient. The University of Maine Cooperative Extension’s first rule for season-extension structures is simple: pick a spot with well-drained soil and full sun exposure. Everything else, wind shelter and frost avoidance and utility access, builds on those two non-negotiables.
Walk your property before you commit. The most sheltered, sunniest corner on a January morning is rarely the spot you would guess in June, when the trees are full and the sun rides high. The factors below are ranked roughly by how much they affect day-to-day growing, sun first, convenience last.
Light is the single most important siting factor. Aim for a spot that receives at least 6 hours of direct, unobstructed sun per day, measured in the growing season you care about most. The RHS advises siting a greenhouse where it can receive uninterrupted sun throughout the day, and short of that, more sun always beats less.
The threats to that sun are shadows, from trees, buildings, fences, and your own house. Shadows are longest in winter when the sun sits low, so a fence that clears the glass in July can shade it completely in December. Deciduous trees are the trickiest case: they cast dappled shade all summer when you want maximum light, then drop their leaves and let cold winter wind through when you want shelter.
Give obstructions room. Use these minimum clearances as a starting point, then add margin on the south side, where shadows fall, and for trees that are still growing:
| Obstruction Type | Minimum Clearance |
|---|---|
| Deciduous trees | 25+ feet |
| Evergreen trees | 15+ feet |
| Buildings | 10+ feet |
| Fences | 5+ feet |
These are floors, not targets. A 40-foot oak on your south boundary will throw a winter shadow well past 25 feet, so judge each obstruction by the shadow it actually casts at the time of year you plan to grow.
Orientation, which way the long axis points, is a refinement once the site is chosen, not a site-selection factor on its own. In the northern hemisphere the long side generally faces south to capture the most light. For the full breakdown by climate and crop, see what direction a greenhouse should face.
Wind is the factor most people underestimate, and it does damage on two fronts. A greenhouse in an exposed, gusty spot loses heat fast as wind strips warmth from the glazing, and a strong enough gust can lift panels or rack the frame. The RHS specifically recommends screening from cold winds, which keep spring temperatures low and slow young plants.
The goal is shelter without a wind tunnel. A hedge, solid fence, or wall on the windward side breaks the gusts, and the leeward side of a slope or building is naturally calmer. What you want to avoid is the gap between two buildings or a narrow side-yard, where wind funnels and accelerates. If your only sunny spot is also windy, plan to anchor the greenhouse properly and add a windbreak set back far enough that it does not cast shade.
Cold air behaves like water: it flows downhill and pools at the lowest point it can reach. Low ground and the base of a slope collect that cold air on still nights and can run several degrees colder than ground 20 feet uphill, enough to mean the difference between a light chill and a killing frost inside the greenhouse.
Site the greenhouse above the cold-air pool, not in it. Mid-slope spots with open air drainage downhill stay warmer than valley bottoms and dips. Watch for cold-air dams too: a solid fence or wall across a slope traps the cold air flowing toward it and creates a frost pocket on the uphill side. If you are weighing a low, sheltered hollow against a slightly more exposed shoulder of the slope, the shoulder is usually the warmer, safer bet on frosty nights.
The most beautiful site is the wrong one if you dread walking to it. A greenhouse needs near-daily attention in the growing season, watering, venting, checking, so keep it close enough that tending it stays a pleasure, not a chore. Leave a path wide enough for a wheelbarrow or cart to reach the door.
Utilities decide a lot too. Running water within easy reach saves hours over a season, and power matters the moment you add a fan, heater, or automatic vent. Siting near the house makes connecting a buried water line or electrical circuit far cheaper than trenching across the yard. A spot near an existing outdoor spigot and outlet is the path of least resistance, and a position close to the home also picks up a little radiant warmth from the building on cold nights.
Greenhouse gardeners almost always want more space within a few seasons. Leave at least 1 meter (about 3 feet) of clear ground on all four sides of the structure from day one. That clearance does triple duty: it gives you access to every panel for cleaning and repair, room to open side vents fully, and the option to extend the greenhouse or add a second one later without tearing out a bed or a path.
Tight siting against a shed, fence, or wall feels efficient until a panel cracks and you cannot reach it, or until the day you wish you had built bigger. Plan the footprint, then plan the breathing room around it. Our greenhouse buyer guide covers matching the structure size to your space, and the best greenhouse kits roundup lists footprints so you can check clearances before you buy.
Walk the property and rank your candidate spots against the checklist below, in this order:
When two sites tie, let sun and drainage break the tie, those are the hardest to fix after the fact. Wind and utilities can be improved with a windbreak, a hose, or an extension cord; a shaded or soggy site cannot.
A greenhouse needs at least 6 hours of direct, unobstructed sunlight per day for healthy, productive plants, and more is better. Measure sun in the growing season you care about most, since winter shadows fall much longer than summer ones. If a spot drops below that for large parts of the day, expect slower, leggier growth.
Keep at least 25 feet from deciduous trees, 15 feet from evergreens, 10 feet from buildings, and 5 feet from fences. These are minimums. Add margin on the south side where shadows fall, and account for trees that are still growing and for the long, low shadows cast in winter.
A frost pocket is a low spot where cold air pools on still nights, running several degrees colder than nearby higher ground and raising the risk of frost damage. Avoid it by siting the greenhouse above the base of any slope, on ground with open air drainage downhill, and away from solid fences or walls that dam cold air on a slope.
Ready to find the structure to match your spot? Browse our greenhouse kits for sale to compare sizes and footprints, then site it for sun, shelter, and room to grow.
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