Collection: Outdoor greenhouse

What an Outdoor Greenhouse Gives You

An outdoor greenhouse creates a sheltered growing space through the British seasons. Glazing traps daytime heat, the structure blocks wind, and the enclosure keeps off the heavy rain that flattens crops in an open bed. The combined effect is a longer season at both ends and steadier conditions in between.

The practical result is that crops which struggle outdoors become reliable. Tomatoes, cucumbers, peppers and chillies all need more consistent warmth than a British summer supplies, and all four are straightforward under glass.

Heat Has to Be Managed, Not Just Trapped

The same glazing that holds warmth in April will overheat the house in July. An unvented greenhouse on a sunny day can pass thirty five degrees while the air outside sits at twenty, which is past what most crops tolerate.

• Roof vents let hot air out at the top where it collects.
• Louvres at low level draw cooler air in, which is what actually moves air through.
• Shading cuts the load before it enters, which is more effective than removing it afterwards.

An automatic vent opener handles this without power or attention. It is the single most useful addition to an outdoor greenhouse and prevents most heat losses.

Choosing a Size

Sizes run from compact frames of two square metres up to full walk in houses. The most common choice in British gardens is between five and ten square metres, which holds staging along one side and a bed along the other with a path between.

The size guide sets out what each band allows. Measure the ground you have, then subtract clearance for the door to swing and room to walk around for cleaning and glazing repairs.

Siting

An open position away from buildings and trees gives the most light, particularly in winter when the sun is low and shadows are long. Check what shades the site through a whole day rather than at the moment you look.

Avoid siting under trees. Falling branches break glass, and leaf litter and sap on the glazing cut transmission and are tedious to clean off.

Base and Anchoring

The base carries the frame and keeps it square. Level, drained and square is the requirement, whether that is slabs, a concrete perimeter or a proprietary base frame.

Anchoring is separate and equally necessary. An anchor kit fitted during assembly is what keeps the structure where you built it.