Annual
How to grow nasturtiums
Tropaeolum majus
Sow nasturtium seed 2 cm deep, direct into the soil, from mid April to May in full sun, and it flowers from June until the first frost. The soil is what matters: it must be poor and free-draining. On rich or fed ground nasturtiums make a mound of leaves that hides a handful of flowers. Choose bush types for edging and pots, trailing types for baskets, banks and climbing up netting.
- Hardiness
- Half-hardy annual
- Position
- Full sun
- Soil
- Poor, free-draining
- Ideal pH
- 6.0 to 7.5
- Water
- Low
- Feeding
- Light feeder
Sowing and planting nasturtiums
WhenSow Apr to May direct; flowers Jun to Oct
Starting off
Sow direct Apr to May 2 cm deep, two seeds per station, thinning to one; germination takes 10 to 14 days at 13 to 18 °C. For earlier flowers sow singly in 7 cm pots in Apr indoors and plant out after the last frost, disturbing roots as little as possible.
Spacing and planting
Bush types 30 cm apart, trailing types 45 cm; sow 1.5 to 2 cm deep. Fine in a 25 cm pot or hanging basket, where trailing types spill 1 m.
Varieties worth growing
- 'Empress of India'
- Compact bush type with dark blue-green leaves and deep crimson flowers; the best colour contrast of any.
- Alaska Series
- Bush type with cream-marbled leaves, so it looks good before and between flowers; mixed or single colours.
- Whirlybird Series
- Spurless, upward-facing flowers held above the leaves on a neat 25 cm plant; made for pots and window boxes.
- 'Jewel of Africa'
- Trailing or climbing to 2 m with variegated leaves and flowers in yellow, red, cream and peach; for fences and banks.
- 'Black Velvet'
- Very dark maroon-red velvety flowers on a small bush plant; striking in a salad.
Nasturtiums month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Nothing to do.
- February
Nothing to do.
- March
Buy seed. Too early to sow.
- April
Sow singly in 7 cm pots indoors, or direct under fleece from mid month in a mild garden.
- May
Main direct sowing, two seeds per station. Plant out pot-raised plants after the last frost.
- June
Thin to one per station. First flowers. Check for blackfly.
- July
Flowering. Pick flowers and young leaves for salads. Look under leaves for butterfly eggs.
- August
Cut back straggly growth; it regrows in three weeks. Pick green seed pods for pickling.
- September
Flowering continues. Save ripe seed that has dropped, dry it and store in paper.
- October
Pull and compost after the first frost. Leave dropped seed if you want volunteers.
- November
Nothing to do.
- December
Nothing to do.
Feeding nasturtiums
Do not feed nasturtiums. Poor, dry soil gives the most flowers and any fertiliser gives leaves instead. The one exception is a starved plant on pure sand or in spent compost.
Poor soil gives the most flowers, rich soil gives all leaf.
Feeding plan
Sowing and all season, in the ground
No feed
None. No compost, manure or fertiliser; choose the poorest sunny spot you have.
Sowing, pots and baskets
No feed
None. Use multipurpose compost cut with a third grit or sharp sand, or re-use last year's spent compost.
Midsummer, only if plants are tiny with yellow older leaves
1 g per litre of water as a single drench: 5 g in a 5 litre can. Do not repeat unless the yellowing returns.
This plant should not be fed. Seaweed Extract Powder is listed only as a one-off rescue for starved plants; the live entry also links Kelp Meal, which this plan does not use.
Signs to watch
Lush leaves hiding the flowers
Nitrogen excess from rich soil or feed
Never feed; grow on poor, dry ground
Yellow older leaves and tiny plants on pure sand
Nitrogen short
One dilute seaweed feed
Leaves wilting in a basket
Dry roots
Water daily in Jul to Aug
Pests, diseases and problems
Leaves stripped to the veins by yellow, black and green caterpillars from July
Large and small white butterflies, the 'cabbage whites', which lay on nasturtiums as readily as on brassicas
Check under leaves weekly and rub off the yellow egg clusters; pick caterpillars off by hand. Plants regrow after an attack. If you grow them as a decoy near cabbages, expect to lose leaves.
Shoot tips and leaf undersides black with insects, leaves curled and sticky
Black bean aphid (blackfly)
Pinch off the worst shoots and hose the rest. Plants grown hard on poor soil suffer less than lush, fed ones. A sacrificial plant covered in blackfly should be pulled and binned before the aphids move on.
Seedlings eaten off at soil level
Slugs and snails
Sow two seeds per station, protect with wool pellets until plants have four leaves, or start singly in 7 cm pots.
Seedlings blackened, or sitting still with purple leaves, after an April sowing
Frost or cold soil; nasturtiums are killed by any frost
Cover early sowings with fleece on cold nights, or wait until May, when seed germinates in 10 days and catches up.
Pruning
Pruning and care
Pinch off seed pods to keep flowers coming, or leave late flowers to self-seed. Cut back straggly growth in Aug and it regrows within three weeks. No staking; trailing types can be tied to netting to climb 1.5 m. Killed by the first frost, so pull and compost in Oct.
Good to knowEdible flowers and leaves.
Growing nasturtiums in pots
Nasturtiums do well in pots, baskets and window boxes as long as the compost is lean. Use a 25 cm pot or larger, fill it with multipurpose compost mixed with a third grit, or with spent compost from last year's pots, and sow three seeds 2 cm deep in May. Bush types such as Whirlybird stay tidy; trailing types hang a metre from a basket. Water when the leaves just begin to flag, which is daily in July and August for a basket, and never add feed to the can.
Nasturtiums: common questions
Why do my nasturtiums have lots of leaves but no flowers?
The soil is too rich, or they are in too much shade. Nasturtiums flower best on poor, dry ground in full sun, and any compost, manure or fertiliser pushes them into leaf. Stop feeding, do not water unless they wilt, and next year sow them in the poorest spot you have.
Can you eat nasturtiums?
Yes, the flowers, leaves and green seed pods of Tropaeolum majus are all edible and taste peppery, like watercress. Use flowers and young leaves in salads and pickle the green pods as a caper substitute. Only eat from plants you have grown yourself without sprays.
Do nasturtiums come back every year?
The plants do not survive the first frost, but they often return from seed. The large seeds drop in autumn, some survive a mild winter in the soil, and seedlings appear in May. Pull out any you do not want; they are easy to spot.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.