Heavy Duty Ground Anchors Review: Will They Hold a Trampoline in a Storm?

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My garden polytunnel is basically a giant plastic parachute, and every storm season the wind does its best to launch it over the fence. What holds it down is a set of orange screw-in ground anchors and straps. They work really well, they’re solid, and they’ve kept it on the ground through storms. That’s the reason I’d recommend this style of anchor to anyone with a trampoline, a gazebo or a greenhouse to worry about.

This review covers the Andes heavy duty ground anchors, sold in a pack of four. They’re the same design as the set I use on the polytunnel: a long plastic thread you wind into the ground, an eye at the top to tie down to, and a clear tube that turns out to be the cleverest part of the whole thing.

Why Ordinary Pegs Pull Out in a Storm

A normal knock-in peg is held by friction along a thin spike. That’s fine for a tent on a still night. In a storm, the ground is usually soaked, the soil softens, and the wind doesn’t pull steadily. It snatches, gust after gust, and every snatch works the peg a little looser until it pops out and whatever was attached to it heads off down the garden.

A screw thread works differently. Instead of a thin spike, you’ve got a wide spiral biting into a long column of soil. To pull it out, the wind has to drag up all the earth sitting on top of the thread, not just overcome a bit of friction. That’s why these heavy duty ground anchors hold where pegs give up.

How These Heavy Duty Ground Anchors Work

Each anchor is a thick plastic screw with a deep thread. The screw itself is 24.5cm long, or 29cm including the handle at the top, and 3cm across. The top has an eye for your strap, rope or tie-down to clip through. You’ll also see this kind of thing sold as heavy duty earth anchors or ground screws. They’re bright orange, which matters more than it sounds: you can find them again in long grass, and you’re less likely to trip over one in the dark.

The pack gives you four heavy duty ground anchors, four clear tubes and a carry bag to keep the lot together. You line the point up where you want it, push down and turn. In soft or damp ground they wind in by hand. When the ground is harder, that’s where the tube comes in.

The Clear Tube Is the Clever Bit

Each anchor comes with a clear tube, 25cm long, and it does two jobs. In storage, it slides over the screw and covers the thread, so the anchors don’t snag the bag, scratch anything they’re packed with or catch your hand when you reach in for one.

In use, you take the tube off and pass it through the tie-down eye at the top of the anchor. Now it’s a T-bar handle. Holding both ends gives you far more leverage than gripping the top of the screw, so you can wind the anchor down into firm ground without straining your wrists. It works the same way in reverse when you come to take them out.

It’s one of those details you don’t notice in the photos, but once you’ve used it you wouldn’t want an anchor without it.

Holding a Polytunnel Down Through UK Storms

A polytunnel is about the worst thing you can try to keep on the ground in high winds. It’s big, it’s light, and its whole shape catches air like a sail. When a gust gets under the cover, the frame wants to lift. If the fixings let go, you’re not just replacing the polytunnel, you’re hoping it doesn’t land on the car, the house or the neighbour’s greenhouse.

Mine is held down with this style of screw-in ground anchor, with straps over the frame tied down to the anchors. It’s held through the storms. They’re solid, and they work really well.

That’s the real test of heavy duty ground anchors, or heavy duty earth anchors, or whatever the shop calls them. If they’ll hold a giant garden parachute through a British storm, they’ll hold most things you want kept in place.

Will Heavy Duty Ground Anchors Hold a Trampoline?

Trampolines are the classic storm casualty. They’re light for their size, the mat and the safety net catch the wind, and once one gets moving there’s not much stopping it. Every named storm brings a fresh batch of photos of trampolines in roads, on railway lines and on top of other people’s sheds.

A trampoline anchor needs to do exactly what the polytunnel anchors do: stop the frame lifting. Screw an anchor into the ground beside each leg, run a strap over the frame or round the leg, and tension it down to the eye. If these heavy duty ground anchors hold a polytunnel down, a trampoline is well within what they can do. If one does lift, look at how it was fitted before blaming the anchor: it wasn’t screwed in fully, the strap wasn’t tight, or there were too few anchors for the size of the trampoline.

One pack gives you four anchor points. For a bigger trampoline with more legs, buy a second pack so every leg has one. Do it before the storm warning, not during it. Screwing anchors in and tensioning straps in the dark and the rain is nobody’s idea of fun.

Gazebos, Garden Furniture and Greenhouses

A gazebo anchor is the job these were sold for in the first place, along with tents, windbreaks and tarpaulins. The legs of a pop-up gazebo hold almost nothing against the wind on their own, and the roof is a sail. One anchor per leg with a strap or guy line turns it from a kite into something that stays put.

These heavy duty ground anchors are just as useful as everyday garden anchors. A garden bench, a log store, a cold frame, a rotary washing line, a lightweight greenhouse, a water butt stand: anything that can’t come inside before a storm and has a way to strap it down. The listing even suggests one in the pub beer garden to tie the dog’s lead to, and I can’t argue with that.

Getting the Best From Them

• Screw each of the heavy duty ground anchors in until the eye sits at ground level. An anchor left half out has half the grip.
• Use ratchet straps rather than rope where you can. They let you take up all the slack, and a tight strap stops the item rocking, which is what works an anchor loose.
• Set the anchors a little out from the item you’re holding down, so the strap pulls down and slightly outwards.
• In very dry, hard ground, use the tube as a T-bar handle, and wet the spot first if you can.
• After a storm, walk round and check each strap is still tight before the next one arrives.

You can leave them in place for the whole storm season, or unscrew them and put them back in the bag until they’re needed. Either way, it’s worth having a set ready before the forecast turns.

What They’re Not For

These heavy duty ground anchors are for holding things down in soil and grass. They’re not foundation screws for decking, sheds or garden rooms, which are a different, much bigger metal product. They won’t go into a patio, paving or concrete either, so for a gazebo on hard standing you’ll need weights instead. And they’re not a security anchor for locking a motorbike or bicycle to.

For what they are made for, holding light things with a lot of surface area down in the wind, the Andes heavy duty ground anchors do the job properly and pack away small.

What the Rest of the Team Think

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Pros and Cons

Pros

• A deep screw thread grips far more soil than a knock-in peg
• The clear tube covers the thread in storage and doubles as a T-bar handle
• Proven in the wind: this style holds a polytunnel down through UK storms
• Bright orange, so easy to find in grass and less of a trip hazard
• Comes with a carry bag, and the heavy duty ground anchors screw back out for reuse

Cons

• Four heavy duty ground anchors in a pack, so a bigger trampoline needs a second pack
• Need soil or grass: no good on patios, paving or concrete
• Hard, dry ground takes more effort to wind into
• Straps are sold separately

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