Why a Pallet Planter Earns Its Space

In a small garden, the wall is the most wasted surface you own. A vertical planter turns it into growing room, and a reclaimed wooden pallet is just about the cheapest way to get there. A standard UK pallet measures roughly 1200mm x 800mm, which gives you around a square metre of planting face — enough for a decent herb collection, a handful of strawberry plants and a fringe of trailing flowers, all without surrendering a single paving slab.

There is a practical bonus too. Raising plants off the ground improves airflow around the foliage, which means fewer slug attacks and less botrytis on strawberries. The extra height also puts herbs within easy reach of a kitchen door, and it brings the scent of thyme and oregano up to nose level rather than ankle level. If you have a sunny wall, a fence or the side of a shed, you have room for one of these.

Choosing a Pallet Worth Using

Not every pallet is suitable. You want a clean, dry, untreated one, and you need to check what it has been used for. Look for the IPPC stamp burned into the wood.

• HT means heat treated — this is what you want.
• MB means treated with methyl bromide, a fumigant. Avoid these entirely.
• No stamp at all? Leave it. It may have been treated with old-style preservatives.

Avoid pallets that have carried chemicals, powders or anything that has left staining or a strange smell. Pallets used for food deliveries or building materials are usually fine, but give any pallet a good scrub with warm soapy water and let it dry thoroughly before you start. Check for splinters, protruding nails and rotten slats, and pull or hammer down anything sharp.

Tools and Materials

The build is genuinely a half-day job with basic kit.

• A pallet, plus a spare if you want to harvest extra slats
• Pry bar or hammer and crowbar for nail removal
• Medium and coarse sandpaper, or a random orbital sander
• Heavy-duty landscape fabric or woven weed membrane
• Staple gun with stainless steel staples
• Water-based, plant-safe wood preserver
• Peat-free multi-purpose compost and a bag of horticultural grit
• Two treated timber battens, around 50mm x 50mm, cut to the height of the pallet
• Masonry drill, 8mm bit, and frame fixings or heavy-duty screws with wall plugs

Building It Step by Step

Start by deciding which face will be the front. Pallets have slats on both sides, with three stringers between them. You can leave all the slats in place and plant into the gaps, or — for deeper pockets — lever off every other slat on the front face to create open rows. The second option holds more compost and suits larger plants like strawberries and rosemary.

Sand every cut edge and exposed surface until it is smooth to the touch. Then brush on two coats of a water-based, plant-safe preserver, concentrating on the bottom edge and any end grain. Leave it to cure for the full time stated on the tin before planting anything.

Next, line the pallet. Staple landscape fabric across the back face, then wrap it around the bottom and up the lower third of the front, tucking it behind the slats so it does not show. This holds the compost in while letting excess water drain away. Fold the fabric rather than cutting it at the corners, and use plenty of staples — the weight of wet compost will find any weak point.

Fix the two battens vertically to your wall or fence, spaced to match the pallet's stringers, then screw the pallet to the battens. The gap behind allows air to circulate and stops the timber sitting damp against the wall. If you are mounting on a fence panel, think twice: a filled pallet can weigh well over 100kg when saturated, and a fence is not built for that. A brick or block wall, or a sturdy shed, is a far better host. Alternatively, stand the pallet on two short timber feet against the wall and skip the fixings entirely.

Planting It Up

Fill the pallet with a mix of roughly three parts peat-free multi-purpose compost to one part grit. This improves drainage, which matters enormously in a vertical planter. Firm it gently as you go, working from the bottom upwards, and leave about 25mm of clearance below the top slat so water does not run straight off.

Now plant into the gaps between the slats, or into the pockets you created. A good arrangement:

• Top row: trailing plants — nasturtium, trailing lobelia, ivy-leaved pelargonium or calibrachoa — so they cascade over the face.
• Middle rows: strawberries. Alpine or everbearing varieties crop over a long season and cope well with the limited root run. Space them about 200mm apart.
• Lower and side pockets: herbs. Thyme, oregano, sage, chives and parsley all thrive. Keep mint in its own pocket in a sunken pot, or it will swamp everything.

Water the whole thing in thoroughly and let it settle for a few days before adding anything else. Gaps will appear as the compost sinks — top them up.

Keeping It Thriving

Vertical planters dry out faster than borders, because every pocket is exposed to wind and air on more than one side. In high summer, expect to water once in the morning and again in the evening. A drip line or soaker hose run along the top row, on a timer, takes the guesswork out and is well worth the small outlay.

Mulch the surface of each pocket with a centimetre of gravel or wool pellets to slow evaporation. Feed weekly with a liquid tomato feed once flowering starts, which keeps strawberries cropping and herbs leafy rather than woody. Trim herbs regularly to keep them bushy, and pinch off strawberry runners so the plants put energy into fruit instead of offspring.

Rotate your planting each spring, moving strawberries and herbs to different pockets, and top up the compost with a fresh handful or two. Treated well, a pallet planter will give you five or six productive seasons from a piece of wood that was heading for the skip.