Arugula.

Conditions at a glance

• Light Sun in spring and autumn · light shade in summer heat
• Warmth Cool-season · germinates from around 4–13 °C
• Humidity Not fussy
• Water Keep the soil moist — dry spells push it to bolt
• Pot size A container at least 30 cm wide; shallow is fine
• First harvest 4–6 weeks · seedlings up in 5–7 days

Grow it in your space

1. Sow thinly, about 1 cm deep — in a short row, or simply scattered across a pot.
2. Expect seedlings in 5–7 days. It germinates readily even in cool soil, which is why it is one of the first things you can start and one of the last.
3. Thin gradually as they grow and eat the thinnings. Leave about 15 cm between plants if you want full-sized ones; crowded is fine for baby leaves.
4. Keep the compost moist. Heat and dryness together are what send it to seed early.
5. From late spring to late summer, put it somewhere in light shade — it crops for noticeably longer there than in full sun.
6. Sow a small new batch every 2–3 weeks instead of one big sowing. One tray of arugula is over quickly; three staggered ones are a supply.

How to tell it's ready

• Take a few leaves per plant, not the whole plant — cut-and-come-again: work along the row taking the outer leaves. The plant keeps producing from the centre and the growth stays young and tender.
• Young leaves are mild, older ones are hot — flavour builds with size and with heat. If it has become stronger than you like, pick smaller and pick sooner.
• A flower stem means the clock has run out — once it starts to bolt the leaves go bitter and stay that way. The flowers are edible and peppery, so it is not wasted — but sow a fresh batch.

Watch-outs

• Bolting in heat — shoots up a flower stem and the leaves turn harsh — the usual cause of disappointment. Grow it in the cooler ends of the season, keep it watered, and give it shade in summer.
• Flea beetles — leaves peppered with tiny round holes. Cosmetic on established plants but hard on seedlings; a fine mesh over the pot while they are small is the simplest answer.
• Downy mildew — yellowing patches with a greyish bloom underneath — crowded, damp, still air. Thin the sowing and give it more space between plants.
• Sown too thickly — a dense mat of seedlings competing with each other stays small and bolts sooner. Thinning feels wasteful; it isn't, and you eat what you pull.