What staging should I put in a greenhouse, and where?

The commonest greenhouse mistake after ventilation is fixed staging down both sides. It looks efficient in the catalogue and it makes it impossible to grow anything tall. A greenhouse changes use completely between March and July, and the staging has to change with it.

Step by step

1. Plan for two seasons, not one.March: benches full of seed trays and pots, floor barely used. July: tall crops in the border or in large pots, benches mostly empty. The greenhouse layout has to accommodate both, which means at least some of the staging must be removable.
2. Put fixed staging on the north side.The north side receives the least direct light, so it is where staging costs you least. Keep the south side for the border or for tall crops, where the light is.
3. Set the height for working, not for storage.800 to 900mm is comfortable to work at standing up. Lower staging is harder on the back; higher staging puts seedlings too close to the roof glass where they scorch and dry.
4. Add a second tier only where it does not shade.A narrow shelf high on the north wall is useful for hardening off and for trays that want maximum light. A wide upper shelf over the main bench shades everything below it.
5. Leave space under the staging and use it well.The shaded space under a bench suits forcing rhubarb and chicory, storing dormant pots, overwintering fuchsias and keeping compost bags. It is not wasted space unless you treat it as such.
6. Match the surface to the job.Slats where you want airflow around potted plants. Solid or sand where you want even moisture for seed trays and cuttings. Many people run one of each along the same bench run.
7. Keep the path wide enough for a barrow or a bucket.A path you have to shuffle sideways along makes every job harder. In a 6ft wide house, staging down one side only is usually the right decision.

Tips

• Aluminium staging bolts to the greenhouse glazing bars with the manufacturer's channel bolts, which is much more stable than freestanding legs on an uneven floor.
• A sheet of rigid plastic mesh over slatted staging turns it into a stable surface for cell trays without losing the airflow underneath.
• Clean and disinfect the staging every autumn. Bench joints and the undersides of slats are where red spider mite and whitefly overwinter.

Common mistakes

• Fixed staging down both sides of a small greenhouse — It permanently removes the ability to grow anything tall, which is what most people actually want a greenhouse for. Keep at least one side clear or removable.
• Solid staging in a poorly ventilated house — It traps humid air under the bench and around the pots. In a house with only one vent, slatted staging is the safer choice.
• Building staging so wide you cannot reach the back — 600mm deep is comfortable to reach across; 900mm is not, and the back row gets neglected and dries out.

Alternatives

• Slatted aluminium staging: The default. Light, rustproof, and the gaps let air circulate around pots and let light through to whatever is below. Easy to move and to store. Small pots and cell trays can be unstable on wide slats — a sheet of mesh over the top solves it.
• Solid-topped staging: A continuous surface, often used with a layer of sand or capillary matting for self-watering. Good for seed trays and for propagation, but it blocks light to the space beneath and holds moisture, so it needs to be somewhere air moves.
• Sand or gravel tray benches: A shallow tray of damp sand on solid staging. Pots stand on it and draw water up by capillary action, which evens out watering enormously and is excellent for a holiday. Heavy, so the staging must be strong.
• Timber staging: Warmer to the touch, easy to build to fit exactly, and easy to fix hooks and shelves to. It stays damp, harbours pests in the joints and eventually rots, so it needs annual cleaning and treating.
• Removable or folding staging: Trestles, folding benches or staging that lifts off its legs. The right answer for a small greenhouse, because it comes out in May to let the tomatoes have the floor and goes back in September.

Questions people ask