James Whitcombe
Why deep beds earn their keep in a cottage garden
A cottage garden is generous, informal, and packed with flowers, herbs, and vegetables growing cheek by jowl. Raised beds give that abundance a workable structure without making it look regimented. The real gain is depth: a bed 30–45cm (12–18in) high lifts the soil closer to your hands, so planting, weeding, and harvesting stop being a test of your lower back. Deep beds also drain faster in wet winters and warm up sooner in spring, which suits lavenders, lupins, and climbing roses as well as carrots, chard, and strawberries. In a rural plot, they double as a practical edge: you can sit on the timber, rest a trug, or tuck a cloche over a row without fighting the ground.
Choosing untreated timber and getting the size right
Use untreated timber. Treated wood may last longer, but the chemicals can leach into the soil you are trying to nurture. Oak, larch, and Douglas fir are traditional choices; untreated boards will give you seven to ten years, and oak can double that. Aim for boards around 4–5cm (1.5–2in) thick. A bed 1.2m (4ft) wide is the cottage-garden standard: you can reach the middle from either side without stepping on the soil. Length is your choice, though 2.4m (8ft) is easy to work around and suits a pair of beds flanking a grass path. For depth, 30cm (12in) is the minimum for most vegetables; 45cm (18in) is kinder on the back and gives roots like parsnips room to stretch. If your ground is heavy clay, go deeper still and add a layer of grit at the base.
Setting out and assembling the frame
Mark the footprint with string and canes, then strip the turf. You do not need to dig deep; just level the ground and firm it. A slight fall is fine, but a wobbly bed will twist as the timber dries. Set the first board on its edge and check with a spirit level. Butt-joint the corners and drive 150mm (6in) galvanised screws through the overlapping boards. Add a corner post inside each corner for rigidity, or use metal corner brackets if you prefer. For a long bed, add a central brace to stop the sides bowing when the soil is wet. If you are on a slope, step the bed down in sections rather than cutting boards at an angle. Line the inside with cardboard before filling; it suppresses weeds and rots away by the following season.
The filling mix – compost, topsoil, and grit
Fill the bed with a blend that holds moisture but never sits soggy. A reliable recipe is 60 per cent topsoil, 30 per cent well-rotted compost or manure, and 10 per cent horticultural grit. Mix it in a barrow or tip it in layers and fork it together. Do not use pure compost; it shrinks, dries out, and can become hydrophobic. Do not use subsoil straight from a hole; it is lifeless and compacted. If you are filling a 1.2m x 2.4m bed to 30cm, you will need roughly 0.85 cubic metres of mix. Leave a 5cm (2in) gap below the rim so you can water without washing soil over the edge. Tread the mix lightly as you go, then rake the surface level. A scatter of blood, fish and bone before planting gives young roots a gentle start.
Planting, weeding, and harvesting without the ache
Once the bed is full, the height does the hard work. You can sow directly into the surface, or plant out modules with a trowel while standing upright. For a cottage-garden look, ignore strict rows. Group tall plants like cosmos and hollyhocks towards the back or centre, and edge with nasturtiums, violas, and alpine strawberries. Interplant quick crops such as radishes and lettuce between slower brassicas and dahlias. Weeding becomes a ten-minute job with a hoe: slice the seedlings off at soil level on a dry morning and leave them to wilt. Harvesting is easier too. Cut chard and spinach leaf by leaf, pull carrots while the soil is moist, and pick runner beans before they string. Because the bed is deep, you can grow storage roots and maincrop potatoes without forking the ground into a muddle.
Keeping the timber and soil in good heart
Each autumn, spread a 5cm (2in) mulch of well-rotted manure or leaf mould over the surface. Worms will pull it down, feeding the soil and protecting the timber from splashing rain. Check the screws and corner braces every spring; tighten any that have worked loose. If a board starts to soften at the base, replace it before the whole side fails. Rotate your crops in the bed – legumes one year, brassicas the next, roots after that – to avoid tired soil and persistent pests. Never walk on the bed itself. Keep a plank or a flat stone nearby to kneel on when you need to reach the centre. With a little yearly attention, an untreated timber bed will crop generously for a decade or more, and your back will thank you for every season of it.
