When to plant Nasturtiums in London

Sow seeds into individual modules around 7th March - 21st March. Cover with 1 cm of compost and keep the compost just moist while seedlings emerge.

When seedlings have a couple of true leaves, from 21st March to 18th April, move them into individual pots if their modules are crowded. Handle them by the leaves, not the stems, and keep them in bright light so they do not become leggy.

From 4th April to 25th April, move plants outside for longer each day before planting them out. Protect them from cold nights and strong wind, and keep them in a sheltered spot at first.

Once the soil has warmed and frost risk has passed, plant out your hardened-off seedlings around 18th April - 2nd May. Space them 30 cm apart, water in thoroughly straight after planting, and give them a sunny spot with free-draining soil.

From 18th May to 10th November, remove fading flowers regularly so the plant keeps producing new blooms instead of setting seed. Water only in dry spells, because rich soil and heavy feeding usually mean more leaves and fewer flowers.

Pick flowers and young leaves from 18th May until 10th November. Harvest in the morning for the best flavour, and take only a few leaves from each plant so it keeps flowering well.