Some people screen off their greenhouse with hedges or trellis. Why? Choose a greenhouse that’s a pleasure to look at and spend time in and you won’t want to keep it in the dark.
Identify the space for your greenhouse, planning for maximum light: you can provide shade when needed, but you can’t add more sunlight. If direct light will vary with the season (because the sun dips behind hills or gets blocked by growing trees), remember that plants like tomatoes need direct sunlight to ripen, but light in early spring accelerates young plants.
2. Size Matters
Get a big enough greenhouse or resign yourself to fewer plants. Calculate how much space is needed for a given number of plants, bearing in mind that adjacent plants shouldn’t touch when grown. It’s wiser to have space to spare than to add a sprawl of extra sheds, greenhouses and frames later.
3. Think Tall
Space is also upwards. Most free-standing aluminium-framed greenhouses are low-roofed because stability in windy weather depends on the ratio of height to width. One with a small footprint will be good for shelves of seed trays, but for tall or climbing plants they lack height. Height allows you to enjoy the space in other ways too.
4. Choose Style
Planthouse styles have a low skirting wall of timber or brick. The glazed frame sits on top, increasing the height of the roof. This creates space for tall plants and is more pleasant for people, with windows at standing height and the option of an entrance in the side instead of the gable. With good looks and head height, your greenhouse doubles as a sun-lounge.
Brickwork can be matched to your house. Frames of red cedar are rot-resistant and pest-repellent. Planthouse styles have other advantages: pebbles thrown by mowers won’t crack bottom panes, and walls store some heat for the cooler evenings.
Lighting, propagators and heaters are a necessity for some and a luxury for others. Water and electricity are easily piped from the house but should be fitted deep and professionally.
In dry spells it can be forbidden to water gardens from the mains, so install butts to collect rainwater from gutters.
6. Plan Details
An alternative to concrete, timber or brick floors is gravel spread over landscape fabric. Spray it with water to cool the greenhouse down.
Louvre panels can be incorporated into your design for adjustable ventilation. Cold frames nestle conveniently into low-walled designs.
If you’ve chosen a fully glazed frame, don’t waste it by having everything at table height with only tools and pots stacked beneath.
7. Get the Best Plants
Source only healthy and vigorous plants. Few insect pests or blights introduce themselves – if you take in sick or infested plants, you can guess the consequences.
Save money by not buying unnecessary fertilizers, dubious soil mixes, fumigants and pesticides. Plants not weakened by chemicals and over-breeding rarely suffer illness or insect attack. Remember that ladybirds, lapwings, house spiders and silverfish are on your side.
Forget schedules. If it’s dry water it, and if it’s damp leave it be. Checking regularly is the best strategy.
The best thing you can do to maintain a greenhouse is to enjoy being in it. The rest takes care of itself.