🌼 Nasturtium

Nasturtiums are among the most generous plants: easy from seed, flowering for months, and edible from the leaves and flowers to the seeds. The peppery, watercress-like flavour adds colour and spice to salads, and the flowers come in orange, red, yellow and cream.

They thrive in poor soil, in full sun and in pots, hanging baskets and borders, and they trap blackfly away from beans and brassicas. Trailing types scramble over walls and banks, while dwarf types suit pots.

Varieties to try

Empress of India (dark red flowers, blue-green leaves, compact)Alaska (variegated, dwarf)Tom Thumb (compact, mixed colours)Jewel Mix (double flowers, mixed)Tall Trailing Mix (climbing, to 2 m)Black Velvet (very dark red)

Sow seeds directly outdoors in April to June, 2 cm deep, 25–30 cm apart, where they are to flower, after the last frost. Seeds are large and easy to handle, so are ideal for children. Soak overnight to speed germination, which takes 7–14 days.

For earlier flowers, sow in pots indoors in March and April, in individual biodegradable pots. Plants thrive in poor, dry soil; rich soil gives lots of leaves and few flowers. Harden off and plant out in late May.

Top tips

• Sow in poor soil for more flowers.
• Soak seeds overnight.
• Sow where they will flower.
• Wait until frost has passed.

Little care is needed. Water in dry spells, particularly in pots, but do not feed, as it encourages leaves at the expense of flowers. Deadhead to prolong flowering, and trim back any straggly growth in midsummer.

Blackfly love nasturtiums, which can be useful as a sacrificial plant to keep them off crops. Cabbage white butterflies lay eggs on the leaves; check and remove caterpillars. Dig out the plant after the first frost, or let it self-seed.

Top tips

• Do not feed.
• Deadhead for more flowers.
• Use as a trap crop for blackfly.
• Check for caterpillars.

Watch out for

BlackflyCabbage white caterpillarsSlugs on young plantsFlea beetle

Pick flowers, leaves and young seed pods from about eight weeks onward, in the morning. Pick flowers when fully open, and leaves when young and tender; older leaves can be tough. Regular picking encourages more flowers.

The green seed pods can be picked while still young and used as ‘poor man’s capers’. Pick flowers just before using, as they wilt quickly. Check for insects before eating.

Top tips

• Pick flowers when fully open.
• Choose young leaves.
• Pick green pods for pickling.
• Check for insects.

Add the peppery leaves and colourful flowers to salads, sandwiches, pesto and herb butters. The flowers can be stuffed with soft cheese or used as a garnish for cakes and savoury dishes. The unripe seed pods can be pickled in vinegar to make a caper substitute.

Use flowers and leaves fresh, as they do not keep, though they last a day or two in the fridge in a sealed box with damp paper. Pickled seed pods keep for months in a jar. Nasturtium pesto can be frozen.

Top tips

• Stuff flowers with soft cheese.
• Pickle green seed pods as capers.
• Blend leaves into pesto.
• Use as a colourful salad garnish.