Nemesia

Nemesia: how do you recognise it?

Habit

Compact, branching annual about 20–30 cm tall and 15–20 cm wide.

Foliage

Narrow, lance-shaped, light green and slightly toothed.

Flower

Two-lipped flowers about 2 cm across in short terminal racemes, June to September.

Colour

White, yellow, orange, red, pink, purple or blue; often bicoloured, with a different shade in the throat.

Roots

Fine and shallow: the plant is sensitive to both drying out and excess moisture.

Flowering: June–September · Sowing: March–May · Plants: May · Pruning: July

Why grow it?

• Rich, colourful flowering from June to September in almost any shade you could want.
• Compact and low: perfect for edges, window boxes, pots and small gardens.
• Bees visit the small flowers.
• Cutting back after the first flowering gives a second flush in late summer.
• Cheap and easy to grow from seed in a single season.

Nemesia: where does it grow best?

• Sun or light partial shade; in a very hot spot flowering stops sooner.
• Light, well-drained soil: sand or loam, acid to neutral; no wet clay.
• Moderately moist; it likes cool summers and soil that stays evenly moist but never wet.
• Space 15–20 cm apart in borders; in a pot or container they may stand closer.

Light

Sun

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

0.3 m tall, 0.2 m wide

Hardiness

Tolerates light frost (to -2 °C)

Goes well with

• Lobelia: Small blue flowers that go well with warm nemesia colours in a container.
• Verbena: Long-flowering and sun-loving, together a colourful container.
• Petunia: Bigger flowers beside the small nemesia blooms.
• Silver ragwort: Silvery-grey foliage that makes the flower colours stand out.

Nemesia: when and how to plant it?

Plant in May.

1. Sow in March–April indoors at about 15–18 °C. The seed is fine: cover it only thinly with soil or vermiculite.
2. Prick out the seedlings into small pots once they have two true leaves, and keep them light and cool.
3. Pinch out the tips when plants are 8–10 cm tall for bushy, compact growth.
4. Plant out at the end of May after a short hardening-off, 15–20 cm apart.
5. Water in straight away and keep the soil moist for the first few weeks.

Care

Water

Keep the soil evenly moist, especially in pots and containers. A hot, dry spell quickly halts flowering.

Feeding

In containers, a low dose of flower feed every two weeks; in borders, compost at planting is enough.

Deadheading

Cut off spent flowers to prolong the display.

Cutting back

After the first flush, around mid-July, cut the plant back by about half. Water well and feed a little: it flowers again after a few weeks.

Mulching

A thin layer of mulch keeps the soil cool and moist.

Tip: Sow in March–April indoors at 15–18 °C. It likes cool summers: water well and cut back after the first flowering for a second flush.

Nemesia: when to prune it?

Pruning months: July.

When: From late June to mid-July, as soon as the first flush is over; an annual is not otherwise pruned.

How:

• Cut the whole plant back by about half, just above a few healthy leaves.
• Then water and give a little flower feed so that new shoots grow quickly.
• Afterwards remove spent flowers regularly.
• Pull the plant up in autumn and tidy the bed.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Sowing

In March–April indoors at about 15–18 °C. The seed is fine: sow thinly and barely cover. Germination takes 1–2 weeks.

Cuttings

Good forms can be rooted from cuttings of 5–8 cm in late summer in damp compost and overwintered frost-free, but sowing is much easier.

Nemesia: how does it get through the winter?

Hardy to −2 °C: protect in harsh winters.

• An annual: the plant dies in autumn or at the first hard frost. Young plants tolerate a light frost down to about −2 °C.
• Store seed in a paper envelope in a cool, dry place.
• Potted plants can flower a little longer in a bright, frost-free room, but they rarely look good there.

Diseases and pests

• Flowering stops: In heat and drought the plant stops flowering. Water, mulch and cut back; flowers return when the weather is cooler.
• Damping off and root rot: Seedlings collapse or roots rot in soil that is too wet. Use clean, light compost and water moderately.
• Aphids: On young shoots and buds. Rinse them off with water or let ladybirds do the work.
• Spider mites: Fine speckling and webs in hot, dry weather. Misting and keeping the plant from drying out helps.

Through the year

• March: Sow indoors at 15–18 °C.
• April: Prick out. Pinch out the tips.
• May: Plant out at the end of May after hardening off.
• June: Flowering begins. Water.
• July: After the first flush, cut back by half. Feed.
• August: Second flush. Remove spent flowers.
• September: Last flowers.
• October: Clear the plants. Store seed.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The name Nemesia goes back to the Greek nemesion, the name the ancient Greek writer Dioscorides used for a related plant.
• Many modern nemesias in garden centres descend from crosses between South African species.
• Nemesia comes from South Africa, where it grows and flowers in the cooler season.