Why a tiered planter suits small spaces

If your growing space is limited to a balcony, a courtyard, or a tiny patch of patio, every centimetre counts. A tiered planter is one of the simplest ways to multiply your growing area without taking up more ground. By stacking three or four planting boxes at different heights, you lift herbs, flowers, and salads into the vertical space that would otherwise go unused. This means you can harvest more from the same footprint, and you will find the higher tiers are easier to reach, which saves your back during watering and picking. The different heights also create useful microclimates. The top tier is warmer and catches more sun, whilst the bottom tier stays cooler and damper, so you can grow a wider range of plants in one compact unit.

Choosing a spot and planning your build

Before you cut any timber, watch how the sun moves across your space. Most herbs and salad leaves need at least six hours of direct sunlight a day, though leafy greens will tolerate four. A south- or west-facing wall is ideal. Check that you can reach the planter easily with a watering can, and leave about 60cm of clear space in front so you can tend the plants without stretching. A typical three-tier planter measures around 60cm wide, 40cm deep, and 1.2m tall, so it fits neatly against a fence or railing. If you are on a balcony, check the weight limit. Use lightweight compost and consider a two-tier version to keep things manageable. Also think about wind: a sheltered corner will stop tall herbs from drying out or toppling.

Tools and materials for the job

You do not need a workshop full of expensive kit. A basic set of hand tools will do the job nicely. Gather the following:

• Timber: two 1.2m lengths of 50mm x 50mm treated timber for the legs, and three 60cm lengths of the same for the crossbars. For the boxes, you will need 2.5cm thick treated timber: six pieces at 60cm long, six at 20cm long, and three bases at 60cm x 20cm. Ask your timber merchant to cut these to size if you do not have a saw.
• Fixings: 40mm and 60mm exterior wood screws, plus exterior wood glue.
• Tools: a saw, drill, screwdriver bit, tape measure, pencil, and sandpaper in medium and fine grits.
• Finishing: a water-based wood preservative that is safe for plants and pets.
• Growing medium: multipurpose compost, horticultural grit, and a slow-release fertiliser.
• Plants: a mix of herbs, salad leaves, and small flowers.

Cutting, assembling and finishing the planter

Start by sanding all cut ends to remove splinters. To build each box, screw the two 60cm sides to the two 20cm ends, using glue on the joints for extra strength. Pre-drill your screw holes to stop the timber splitting. Attach the base, or leave narrow gaps between slats if you prefer. Drill a few 6mm drainage holes in the base. Next, build the ladder frame. Lay the two 1.2m legs flat on the ground, mark heights at 25cm, 65cm, and 105cm from the bottom, then screw the 60cm crossbars in place. Check that the frame is square by measuring diagonally from corner to corner; the measurements should match. Add a diagonal brace across the back for rigidity. Finally, screw each box to a crossbar through its base. Apply two coats of wood preservative, letting each coat dry completely. This will protect the timber from rain and extend its life for years.

Planting up your tiers (and keeping them thriving)

Line each box with a layer of horticultural grit or broken crocks to improve drainage. Fill with multipurpose compost mixed with a handful of slow-release fertiliser, leaving a 2cm gap below the rim. Plant the top tier with sun-loving herbs such as rosemary, thyme, and oregano, plus trailing flowers like nasturtiums or strawberries. The middle tier suits basil, parsley, chives, and cut-and-come-again salad leaves. The bottom tier, which stays cooler, is perfect for lettuce, rocket, and violas. Water carefully: the top tier dries out fastest, so check it daily in summer. A layer of gravel on the surface of the compost will slow evaporation. Feed with a liquid seaweed tonic every fortnight during the growing season. Because the tiers have different moisture levels, you can group thirsty plants lower down and drought-tolerant herbs higher up.

Simple tweaks for a longer season

A few small adjustments will keep your tiered planter productive from spring to autumn. Place a saucer or drip tray under each box to catch runoff and stop stains on your patio. If your balcony is exposed, secure the frame to the wall with metal brackets. For really tight spots, build just two tiers instead of three. In late summer, sow winter salad leaves in the bottom tier and cover with a cloche or fleece when frosts arrive. Each spring, replace the top few centimetres of compost and clean the boxes with diluted vinegar before refilling. With a little care, this simple piece of woodwork will reward you with fresh herbs and salads for years, no matter how small your growing space.