With increasingly wild weather the only certainty in future forecasts, greenhouse gardeners need to ready their structures for a stormy ride.
Like it or not, increasingly powerful, destructive storms are now wired into the decades – centuries, unless we hit the emergency brake on carbon emissions – ahead. Everyday life, for us and for all the other species we cohabit earth with, is changing. Some changes will creep up on us; others will be abrupt. A heating, turbulent climate, supercharged with energy and increasing moisture, is triggering extreme weather across our planet.
There’s trouble ahead for gardeners in the unpredictable new world we’re growing into. Storms, more frequent and punch-packing, will be a big fist in that trouble. Our greenhouses need to be ready to face down whatever wild future weather throws at us; tempests laden with high winds and gales are the greenhouse gardener’s nemesis.
So we need to be storm-ready, by thinking and planning ahead, checking, adapting, repairing, testing – and then checking again. And once a storm has passed, we need to do it all over again. If you’re mulling getting a new greenhouse, buy the best and the strongest you possibly can.
Here’s a checklist of actions to ready and steady our greenhouses – aged, new or still in the offing – for the pummellings ahead.
Repair, repair, repair
Attending to repairs is the golden rule of storm-proofing any greenhouse. Missing, cracked or loose, rattling glazing tempts more destruction. Replace broken glass (or at least tape over any existing cracks ahead of a storm) and check for missing glazing clips or perished seals around the panes.
If a whole glazing pane has gone and there’s no time to replace it pre-storm, make sure the gap is covered over temporarily, using tough plastic sheet or board taped to the surrounding glass (cardboard shreds in the rain). If several panes are half-missing or cracked, securely tying a tarpaulin (so the wind cannot lift it) over the vulnerable side of a greenhouse temporarily wind-proofs a larger area.
Stay safe: never attempt repairs during high winds.
Play it safe
If you need to replace damaged glass, search online to locate local suppliers able to cut it to the size(s) you need. Consider tougher safety glass for overhead repairs; it shatters into small granules (like a broken windscreen) rather than jagged, dangerous shards. Toughened glass is heavier than standard ‘horticultural’ glass, but it’s also stronger, so is worth investing in if you are retrofitting a pre-loved greenhouse with a sturdy frame.
Batten down the garden
Our gardens are awash with more clutter than ever, much of it ready to take flight in the next storm. Whether it’s terracotta pots, buckets or wheelbarrows, all such objects are capable of being hurled at your greenhouse with enough force to crack and shatter glass, and perhaps damage its frame. Do a pre-storm check for objects that the wind can get inside and carry off, moving them to a calmer part of your plot. Replace rotten or damaged fence panels, which could take flight and smash your greenhouse dreams to smithereens.
Dismantle plastic ‘mini’ greenhouses and store them away, unless you want to gift them to gardeners in the next county.
High wind deals its killer blow when it gets inside your greenhouse. Open doors or vents, and even loose or missing panes of glass, will allow in enough of a bullying gust to damage and break glass. Manual vents can be wired tight shut, while automatic vents – which might try to open during a storm fuelled by warm, humid air – should be dismantled. Fitting foam draught excluder tape around vents makes a tighter, wind-proof seal (and reduces rattle).
Close louvres and shut and latch doors; a recent storm mustered enough force to open the sliding doors of my lean-to. Lacking an internal latch, I wired the doors together until the gale blew out.
To get a true feel for how a typical storm behaves in your garden or allotment, go and bathe in the teeth of one. This gives you a good idea of where the most exposed and the most sheltered parts of your patch are, giving clues as to where to site a new greenhouse – or relocate an existing, currently storm-battered one. Stand in different parts of the garden, observe where rain and autumn leaves are blowing and falling, and any features, such as hedges, which are helping to calm the wind.
Relocation, relocation, relocation
If your greenhouse is plagued by persistent storm damage, relocating it to another part of the garden or allotment is an option. Suss your plot out first with some storm bathing, to find a less exposed spot. Be wary of siting greenhouses between buildings – places you might assume will be more sheltered – which can become full-blown wind tunnels. On an exposed allotment site, consider moving a greenhouse to where the wind is filtered and slowed by trees and hedges on the perimeter (or establish a new communal windbreak using fast-growing willow).
Orientate a greenhouse so the door doesn’t face into the prevailing wind; in the UK, the prevailing wind direction is generally from the southwest.
Before dismantling a greenhouse, take ample photographs, meticulously labelling each component with an indelible pen.
Even if you keep the wind out of a greenhouse, damage to the whole structure is a risk if it isn’t well anchored to a solid, immovable base. Brickwork, blocks, concrete or wooden sleepers make a solid and heavy base. Secure the frame by screwing, or even better, bolting it to the base (for a belt and braces job, add extra fixings to those recommended by the manufacturer). Check and tighten the base fixings regularly.
Brace and strengthen
An existing greenhouse can (providing it is securely anchored to a base) be given extra robustness by adding bracing and other types of support to the actual metal frame. It’s worth checking with the original manufacturer to see what kits and advice are available, or you can dive online for a plethora of tips, solutions and mail order accessories, then let your DIY skills rip.
Break the wind
Living windbreaks – essentially porous deciduous hedges and shrubs – can help to protect an existing greenhouse from storm damage. Windbreaks work not by diverting wind, but by breaking it up, dissipating its damaging force. If space allows, a greenhouse can be surrounded by a living windbreak, providing it doesn’t cast too much shade over the greenhouse itself.
Hazel (Corylus avellana) is a useful wind-slowing shrub that can be regularly coppiced, providing plant supports, mulch and soil-boosting green wood chips. Non-invasive bamboos and large ornamental grasses also help to tame damaging wind, and can be shredded into mulch and compost-making fodder.
Keep a close eye (and ear) on weather forecasts. The relatively new trend of naming storms, tedious as it can feel, does generate chatter and focus ahead of a thrashing. A freshly named storm is your red light for an all-round inspection outdoors – but there’s no harm in checking ahead…
Text and images © John Walker; Depositphotos
Find John on X (formerly Twitter) @earthFgardener