Nasturtium

Tropaeolum majus

Nasturtiums trail along the ground or climb. You can eat both the bright flowers and the peppery leaves. They do best in poor soil that drains well. Rich soil gives you a mass of leaves and few flowers. They're easy to grow from seed, even for children.

Looking after it

Water: Once they're growing in the ground, they cope with dry spells. Water seedlings and plants in pots. If the soil stays very dry for a long time, the flowering stops. Feeding: Nasturtiums need very little, so don't feed them at all. Feeding gives you leaves instead of flowers. Grow them in ordinary or poor soil, without compost or manure.

Cutting and after flowering

Pick young leaves and open flowers in the morning, as you need them. Pick the green seeds before they harden and you can pickle them like capers. Picking off faded flowers keeps new ones coming. Leaves and flowers wilt quickly. Keep them in a bag in the fridge and use them within a day or two.

What can go wrong

Blackfly. Thick clusters of black insects sit under the leaves and on the shoot tips. Pick off the worst shoots or hose them down. Ladybirds and hoverflies soon move in.
Cabbage white caterpillars. Green caterpillars strip the leaves in late summer. They're the same ones that eat cabbages. Check under the leaves and pick them off by hand.
All leaves, few flowers. Big, lush leaves hide just a few flowers, because of rich soil or feeding. Stop feeding. Next year, sow them in a poorer, sunny spot.

Growing facts: RHS, UC ANR and seed-company sowing guides. Nasturtium care: RHS and University of Maryland extension.