Making the Most of Vertical Space with Wall Planters

Why Walls Are the Most Underused Growing Space

Walk around any UK street and you'll see metres of bare brick, render and fence panel doing nothing at all. A south-facing wall is a genuine microclimate: it holds warmth into the evening, shelters plants from wind, and can push you a fortnight ahead of the open ground. Even a north-facing wall earns its keep with lettuces and mint, which bolt quickly in strong sun. The trick is to treat the wall as a growing area in its own right, not a place to hang a token basket by the front door.

Vertical growing suits small gardens, courtyards, balconies and narrow side returns, but it also works brilliantly in a large garden where you want herbs within arm's reach of the kitchen door. The limiting factors are simple: weight, water and light.

Choosing Wall Planters and Fixing Them Properly

Everything rests on the fixing, so start there. A 40cm trough filled with damp compost and mature plants can easily weigh 15–20kg, and that load is multiplied by wind and leverage the further it sits from the wall.

• Know your wall. Solid brick or block takes frame fixings or sleeve anchors well; aim for at least 50mm into the brick itself, not the mortar joint. Render is decorative — fix through it into the wall behind rather than trusting the render alone.
• Fence posts and panels are fine for lightweight baskets and small troughs, but use coach screws and consider a horizontal batten to spread the load across two posts.
• Check for cables and pipes with a detector before you drill, especially on older properties.
• Use a batten rail. Screwing a treated timber rail to the wall and hanging planters from that gives you flexibility and spreads weight beautifully.

For the planters themselves, look for thick-walled plastic, glazed ceramic or powder-coated metal with a decent depth — 20cm of compost minimum for salads, more for anything with a taproot. Shallow decorative pots dry out in hours. Drip trays or integral reservoirs are worth every penny.

What to Grow: Salads, Herbs and Trailing Flowers

Pick plants that cope with a smaller root run and don't mind drying out between waterings.

• Cut-and-come-again salads: rocket, mizuna, loose-leaf lettuce, pak choi and spinach. Sow little and often rather than one big row.
• Herbs: thyme, oregano, sage, rosemary and marjoram all thrive in wall planters. Basil and coriander need more water and prefer warmth. Mint must be kept in its own pot or it will take over.
• Trailing flowers: nasturtium, trailing lobelia, ivy-leaved pelargonium, bacopa and trailing fuchsia. Nasturtium flowers and leaves are edible, and the young seed pods make a decent caper substitute.
• Strawberries are superb in wall planters — fruit stays clean and slugs have further to travel. Try a tumbling tomato variety in a large basket on a warm wall.

Underplant upright growers with something that spills over the edge. It looks generous and it shades the compost, which slows evaporation.

Watering, Feeding and Compost That Actually Works

Wall planters dry out faster than anything at ground level because they catch wind on all sides and reflected heat from the masonry. Assume daily watering from May to September, and twice a day during a heatwave.

• Water in the evening so plants take it up overnight rather than losing it to the sun.
• Group by thirst. Put thirsty crops together and drought-tolerant herbs together so one watering suits the whole row.
• Use a peat-free multipurpose compost with added grit or bark for drainage, and mix in water-retaining granules for baskets.
• Mulch the surface with gravel, wool pellets or cocoa shell to reduce evaporation.
• Feed weekly with a liquid tomato feed once flowering or cropping starts; a seaweed feed fortnightly keeps foliage healthy.

If you're away often, an automatic drip line on a timer is a sensible investment. Test it for a week before you rely on it.

A Seasonal Rhythm for Wall Planters

February to March: sow hardy salads and herbs under cover. Check fixings after winter gales and replace any rusted screws.

April to May: harden off and plant out after the last frost — mid-May in the south, late May to early June further north. Refresh compost in permanent planters.

June to August: keep sowing small batches of salad every three weeks for a continuous cut. Deadhead flowers to extend the display.

September to October: sow winter salad under cover, plant winter pansies and hardy herbs, and tidy up. Clear spent compost from baskets rather than reusing it, to avoid disease build-up.

November to January: plant spring bulbs in deep troughs, protect terracotta from frost damage, and plan next year's planting while the structure is bare.

Small Details That Make a Big Difference

• Turn pots a quarter turn each week so plants grow evenly rather than leaning into the light.
• Watch for vine weevil grubs in containers — if plants wilt despite watering, tip them out and check the roots.
• Net brassicas against pigeons, which quickly find anything on a wall.
• Choose lighter colours on a hot wall; dark planters absorb heat and cook roots.
• Clean and store planters over winter so they last, and check every fixing once a year.

Start with one sunny wall and a single row of troughs. Once you've got the watering routine sorted, you'll wonder why you ever wasted the space.