Building a herb spiral — four climate zones on three square metres

The Herb spiral is probably permaculture's most elegant idea: by spiralling a wall upward you create four different growing positions at once on two to three square metres. At the top it's dry, lean and sunny like the Mediterranean; at the bottom cool, moist and humus-rich. Every herb gets exactly the corner it needs — and everything is within reach at a single spot.

The principle: a mound that turns

The spiral is a small mound (15.7 in–31.5 in high) around which a low dry-stone wall winds. This construction produces several effects at once:

• Height gradient — water runs off at the top (dry), collects at the bottom (moist).
• Compass orientation — the south side is warm and sunny, the north side cooler and shadier.
• Heat store — the stones absorb sun during the day and give off warmth at night, a frost buffer.
• Habitat — the gaps in the wall are shelter for lizards, wild bees and Beneficials.

Location & dimensions

• Full sun, as close to the kitchen as possible (you harvest daily).
• Diameter 4.9 ft–6.6 ft, height in the middle 15.7 in–31.5 in.
• The opening of the spiral and the water zone face south — that's where it's warmest.

Build it — step by step

1. Mark out the area: mark a circle of ~6.6 ft. On heavy soil, dig out 7.9 in and add a Drainage layer of gravel / rubble.
2. Set up the water zone: at the southern foot, sink a small hollow or a buried bucket / bowl as a mini pond. It keeps the lower end permanently moist.
3. Build the dry-stone wall up in a spiral: set natural stones without mortar, rising from outside toward the inside — the wall grows taller toward the tip. Tilt the stones slightly inward, that gives them grip.
4. Fill with a gradient in the substrate:
   • Tip: lean, free-draining material — soil with plenty of sand and grit.
   • Middle: ordinary garden soil.
   • Foot: humus-rich soil with Compost.
5. Let it settle & plant up: let it settle for a few days, then water and set the herbs in by zone.

Which herb goes where?

• Tip (dry, lean, full sun): rosemary, thyme, lavender, sage, oregano — the Mediterranean crowd that loves lean soils.
• South/west slope (free-draining, sunny): savory, hyssop, curry plant, marjoram.
• Foot / north side (humus-rich, fresh, part shade): parsley, chives, chervil, tarragon, lovage.
• Water zone (wet): watercress, mint, water mint — and by the way best kept in pots, otherwise the mint overgrows the whole spiral.

An honest note: mint, tarragon and lovage are rampant spreaders. Plant them directly and you'll be digging them out everywhere within two years. Set in pots, they stay where they're meant to.

Care

• Almost never water the tip — the Mediterranean herbs want it dry. Too much water kills rosemary faster than frost does.
• Replant annuals (basil, dill) each year; cut back perennials in spring.
• In autumn, protect tender herbs (rosemary in cold areas) with fleece or pot them up.
• Every few years, renew the lean substrate at the tip — it turns to humus over time.

In the Garden Planner the herb spiral is its own element — it's automatically placed in the sunny southern half of Zone 1, close to the house, where you harvest daily. It pairs well with an insect hotel nearby: the herb flowers are a magnet for bees.