Cape primrose

Cape primrose: how do you recognise it?

Habit

Stemless rosette about 30 cm tall and 40 cm wide; the leaves are half spreading.

Leaves

Long and narrow, 15–30 cm, crinkled, softly hairy and rather brittle; fresh to dark green.

Flowers

Trumpet-shaped flowers of 3–6 cm with two smaller and three larger lobes, on thin stems above the leaves, from April to October.

Colour

Blue, purple, lilac, pink, red and white, often with a yellow or veined throat.

Fruit

A long, narrow seed capsule that twists open in a spiral as it ripens.

Roots

Fine and shallow: it grows best in a wide, shallow pot.

Flowering: April–October · Plants: March–April

Why grow it?

• Flowers for months, from April to October, with new flower stems all the time.
• A wide choice of colours and patterns, from soft lilac to deep purple and pink.
• Does well in a bright spot out of fierce sun, such as by an east- or north-facing window.
• Easy to propagate: a single leaf can give you many new plants.
• Compact: fits on any windowsill and stays attractive for years if you rejuvenate it now and then.
• A free-flowering alternative to the African violet, with the same simple care.

Cape primrose: where does it grow best?

• Light without direct sun: by an east- or north-facing window, or a little way back from a south- or west-facing one. Fierce sun scorches the leaves.
• Room temperature of 16–24 °C; in winter it can be cooler, but not below 10 °C.
• Moderately humid air; avoid a spot directly above a radiator.
• No cold draughts, and no leaves resting against a cold window.

Light

Bright, out of direct sun

Potting soil

Multi-purpose compost or airy, humus-rich compost

Acidity

Acid or neutral

Watering

Moderately

Size

0.3 m tall, 0.4 m wide

Temperature

Minimum 10 °C

Goes well with

• African violet: A close relative with the same care; together they make a flowering windowsill.
• Begonia: Flowering and patterned-leaved forms for the same bright spot out of fierce sun.
• Moth orchid: Also likes light without fierce sun and water only once the mix has dried a little.
• Nerve plant: Low, veined leaves as a green base next to the flowers.

Cape primrose: when and how to plant it?

Plant in March–April.

1. Repot in March or April when the pot is full of roots, usually every year.
2. Choose a wide, shallow pot with a drainage hole; it flowers best in a pot that is not too big.
3. Use open compost for African violets or houseplants, mixed with about one third perlite.
4. Set the plant at the same depth as before: the base of the rosette must not disappear under the compost.
5. Water in lightly with room-temperature water and let the excess drain away.

Care

Watering

Let the top layer dry out between waterings. Water at the edge of the pot or from below, and keep water out of the centre of the rosette. It copes better with a little drought than with wet feet.

Feeding

From April to September, liquid feed for flowering houseplants every two weeks at half strength.

Deadheading

Cut spent flower stems off at the base so the plant produces new ones.

Leaves

Snip off brown leaf tips and old, damaged leaves; you may thin out a crowded rosette a little.

Repotting

Every spring into fresh compost; divide large old plants at the same time.

Tip: Choose a wide, shallow pot that is not too big and give a little feed every two weeks: a plant that fills its pot well flowers best. Always water beside the rosette, never into the centre.

Cape primrose: when to prune it?

When: Pruning is not needed. You only cut spent flower stems off at the base and remove old or damaged leaves.

How:

• Cut spent flower stems with scissors as close to the base as possible.
• Snip off brown leaf tips; a leaf that has grown too long can also be trimmed straight across.
• Remove old, yellow leaves at the base to let light and air into the rosette.

Pruning calendar and basic rules

Propagation

Leaf cuttings

In spring or summer: cut off a healthy leaf, cut out the midrib along its whole length and insert both halves, cut edge down, 1 cm deep in moist cutting compost. Kept bright and warm under plastic at about 20 °C, small plantlets appear along the veins after a few weeks.

Leaf sections

You can also cut a leaf across into 5 cm sections and stand them upright, bottom end down, in moist cutting compost.

Division

Divide an old plant with several rosettes in March–April when repotting.

Cape primrose: how does it get through the winter?

• A houseplant that stays indoors all year: below 10 °C it suffers damage.
• In winter it usually rests: flowering stops and growth slows. Give it a bright, slightly cooler spot at 12–16 °C.
• While it rests, water less, do not feed and let the compost dry out a little more.
• In March, remove old leaves and repot: it then starts a new flowering season fresh.

Diseases and pests

• Few flowers: Too little light or too little food. Move it somewhere brighter, but out of fierce sun, and feed regularly.
• Limp, drooping leaves: Too dry or, on the contrary, too wet. Feel the compost: if dry, water; if wet, let it dry out and water less from then on.
• Grey mould: Grey fuzz on flowers and leaves, especially in cold conditions with wet leaves. Remove affected parts and do not water over the leaves.
• Thrips: Silvery streaks and specks on leaves and flowers. Rinse the plant and hang up a blue sticky trap.
• Mealybug: White fluff at the base of the leaves. Wipe off with a damp cotton bud.

Through the year

• January: Rest. Bright, cool spot, little water, no feed.
• February: Rest. Remove old leaves.
• March: Repot in fresh compost. Divide large plants. Start feeding.
• April: First flowers. Feed every two weeks. Take leaf cuttings.
• May: Flowering. Cut spent flower stems off at the base.
• June: Flowering. Keep out of fierce sun. Take leaf cuttings.
• July: Flowering. Adjust watering to the heat.
• August: Flowering. Feed. Watch for thrips.
• September: Flowering. Last feed.
• October: Last flowers. Water less.
• November: Rest. Keep bright and slightly cooler.
• December: Rest. Little water.

Did you know?

• The name Streptocarpus means ‘twisted fruit’: the long seed capsule twists open in a spiral as it ripens.
• Since 2015, botanists have also placed the African violet in the genus Streptocarpus; it used to be called Saintpaulia.
• Some wild species produce just one single, giant leaf, which keeps growing throughout their life.