Key takeaways
- Coleus is tender, so it lives outdoors only from early June until the first autumn chill
- Sow from February to April at 20-25°C, pressing seed onto the surface without covering it
- Tip cuttings root in a jar of plain water in one to two weeks
- Pinch the tips every few weeks and snap off flower spikes to keep the leaves bushy and bright
- Outdoors, morning sun with afternoon shade gives the richest colours
- Keep one plant on a bright windowsill over winter and take cuttings from it in spring
Coleus is two plants in one. Outdoors it’s bold summer bedding, filling borders and pots with burgundy, lime, copper and pink. Indoors the same plant is a colourful houseplant for a bright windowsill.
Best of all, you only need to buy it once. Coleus cuttings root in a jar of water in a week or two. Keep one plant going on a windowsill through winter and you’ll have free plants every spring. This guide covers seed, cuttings, bedding, pots and houseplant care.
What is coleus?
Coleus is a tender foliage plant in the mint family. You may see it labelled Coleus scutellarioides, Solenostemon or even Plectranthus. They’re all the same plant, and Coleus scutellarioides is the current name.
Like mint, it has square stems and leaves in pairs. The leaves are the whole show, in patterns and colours few flowers can match. The Victorians loved it for their bold summer bedding schemes.
It’s tender, so it can’t take frost and sulks when nights drop below about 10°C. That’s why it goes outside only for the summer.
How to grow coleus from seed
Sow coleus from February to April at 20-25°C, and don’t cover the seed, as it needs light to germinate. Press it onto the surface of moist, peat-free seed compost. A heated propagator on a bright windowsill is ideal. Seedlings usually appear within a couple of weeks and show their colours early.
Seed is the cheapest way to get lots of plants. A packet of a mixed series such as Wizard or Fairway fills a whole summer border.
Prick the seedlings out into modules or 9cm pots once they’re big enough to handle. Keep them above 15°C in good light. Turn the pots every few days so they grow straight.
A border of coleus grown from a single packet of mixed seed. It’s a cheap way to fill a whole bed with colour.
How do you take coleus cuttings in water?
Coleus cuttings root in plain water in one to two weeks. You don’t need rooting powder, a propagator or even compost. A jam jar on a windowsill does the job.
- Cut an 8-10cm tip shoot just below a leaf joint.
- Strip off the lower leaves so none sit in the water, as they rot.
- Stand the cuttings in a jar of water on a bright sill out of direct sun.
- Top up or change the water every few days.
- Pot them into compost once the roots are 2-3cm long.
You can root them straight into compost if you prefer. Water just makes it easy to watch. The guide to rooting cuttings in water lists other plants that do the same trick.
Tip cuttings rooting in a plain jar of water. Once roots reach a couple of centimetres, pot them up.
Free plants every year from one stock plant
Keep one coleus alive over winter and it will give you plenty of cuttings each spring. Gardeners call this a stock plant.
Choose your favourite plant in late September, before nights get cold. Pot it up and bring it indoors, or root a few cuttings and keep those instead, as they take less room. Keep it somewhere bright at about 12°C or warmer. Water only when the top 2cm of compost is dry.
It barely grows through the dark months. In March it wakes up and pushes out new shoots, and every shoot can become a cutting. By June you’ll have a tray of young plants for free. The guide to overwintering plants covers keeping other tender plants through winter too.
When can you plant coleus outside in the UK?
Plant coleus outside in early June, once nights stay above 10°C. There’s nothing to gain by rushing. Late May may be fine in a mild city garden or the far south. In the north, wait until June.
Harden plants off for a week to ten days first. Stand them outside by day and bring them in at night for the first week. The guide to hardening off bedding and half-hardy plants explains how.
Plant in fertile soil that holds moisture, 25-30cm apart. Water new plants in dry spells for the first month.
In pots, use peat-free multipurpose compost. Expect to water daily in hot spells. Feed every two weeks with a balanced liquid feed at half strength.
One dark coleus with lime trailing plants makes a lovely patio pot. Pots dry fast, so check them daily in summer.
Getting the light right: morning sun, afternoon shade
Coleus colours best with morning sun and shade from around midday. Strong afternoon sun can bleach the reds and scorch the leaf edges. Deep shade causes the opposite problem: dull colour and thin, leggy growth.
An east-facing bed or pot is the sweet spot. So is the bright edge of a tree’s shade, where coleus lights up hostas and ferns. Large-leaved types such as the Kong series hold their colour well in shadier spots. For other plants that cope with shade, see the guide to shade-tolerant annuals.
Bright, dappled shade keeps coleus colours rich and makes it a great partner for hostas and ferns.
Can you grow coleus as a houseplant?
Yes, coleus grows indoors all year on a bright windowsill out of harsh midday sun. Supermarket coleus pots are exactly this plant, and many get thrown out long before they need to be.
Give it bright light and turn the pot every week so it grows evenly. Water when the top 2cm of compost is dry. It’s happiest in a warm room and dislikes cold draughts.
Indoor coleus lives fast. After a year or so it turns woody at the base, so take cuttings and start again. A summer outside does it good, and the guide to putting houseplants outside for summer shows how.
| Summer bedding | Houseplant | |
|---|---|---|
| Spot | Morning sun, afternoon shade | Bright windowsill, out of midday sun |
| Season | Early June to early autumn | All year in a warm room |
| Watering | Daily for pots in hot spells | When the top 2cm is dry |
| Feeding | Half-strength feed every 2 weeks | Half-strength monthly, none in winter |
| Lifespan | One summer | About a year before it gets woody |
A bright windowsill keeps an indoor coleus colourful. Turn the pot weekly so it doesn’t lean towards the glass.
Pinching out and removing flower spikes
Pinch out the growing tips every two to three weeks to keep coleus bushy. Without pinching it grows tall and bare-stemmed. Nip each shoot back to just above a pair of leaves with your finger and thumb. Two new shoots grow from below each pinch. Start when plants are 10-15cm tall.
Remove flower spikes as soon as you see them. The thin blue spikes take energy from the leaves and make the plant leggy. The guide to pinching out fuchsias and bedding plants shows the same technique.
Feed for leaves, not flowers. Use a balanced feed at half strength. High-potash tomato feed encourages the flowers you’re trying to stop.
Pinch just above a pair of leaves. Each pinch gives two new shoots, and the plant gets bushier every time.
Which coleus varieties grow best in the UK?
For seed, the Wizard and Fairway series are easy, reliable choices. Many named varieties are sold as plants and grown from cuttings.
| Variety | Height | Best for |
|---|---|---|
| Wizard series | 30-35cm | Bedding, first-timers from seed |
| Fairway series | 20-25cm | Edging, window boxes, small pots |
| Kong series | 45-60cm | Huge leaves, shadier pots |
| ’Campfire’ | About 40cm | Copper-orange colour, sold as plants |
Trailing coleus types work well in baskets too. The guide to planting and caring for hanging baskets covers that.
Coleus can fill a hanging basket on its own. The leaves keep the show going until autumn.
Common coleus problems and how to fix them
Most coleus problems come from cold, wet compost or the wrong light. Nearly all can be fixed if caught early.
- Wilting. Usually dry compost, fixed with a drink. If the compost is wet, the roots may be rotting. Let it dry a little and move it somewhere warmer.
- Leaves dropping indoors. The plant is too cold. Move it off a cold sill or away from a draughty door at night.
- Scorched or faded leaves. Too much afternoon sun. Move pots into bright shade. New leaves will colour up again.
- Leggy, dull growth. Too little light or pinching. Move it somewhere brighter and pinch every tip.
- Whitefly and mealybugs. Mostly a problem indoors and under glass. Check leaf undersides weekly and squash small groups. For bad infestations use an approved product for that use, following the label.
- Slugs on new plants. Soft June plantings are a target. Check after dark in the first couple of weeks. Established plants cope with the odd hole.
Pets may nibble coleus, and it can upset their stomachs. Keep indoor pots out of reach. More foliage favourites are in the houseplants hub.
Frequently asked questions
Is coleus a perennial or an annual?
Coleus is a tender perennial usually grown as a summer annual in the UK. Cold kills it outdoors in autumn. Indoors on a warm, bright windowsill it can live for years, though old plants get woody and sparse. Most gardeners refresh it from cuttings instead.
Should I let my coleus flower?
No, pinch off the flower spikes as soon as they appear. Coleus is grown for its leaves, and flowering makes the plant leggy and dulls the colour. Check every week from midsummer and snap the spikes off at the base.
Can coleus take full sun in the UK?
Morning sun is fine, but strong afternoon sun can scorch the leaves. The richest colour comes in bright light with shade from about midday, such as an east-facing bed. Some newer varieties cope with more sun. In deep shade colours dull and growth turns thin.
Why does my coleus keep wilting?
Dry compost is the usual cause, and a drink soon perks it up. If the compost is already wet and it still droops, the roots may be rotting in cold, soggy compost. Let it dry a little, move it somewhere warmer and water less often.
How long do coleus cuttings take to root in water?
Usually one to two weeks on a bright windowsill out of direct sun. Take 8-10cm tip cuttings, cut just below a leaf joint, and remove any leaves that would sit in the water. Pot them up once the roots are 2-3cm long. Rooting is slower in winter.
Is coleus poisonous to cats and dogs?
Yes, coleus is listed as toxic to cats and dogs. Chewing it can cause vomiting and diarrhoea. Keep indoor pots out of reach and grow outdoor plants where pets don’t nibble them. Call your vet if your pet has eaten some.
Can you keep coleus over winter in the UK?
Yes, bring it indoors to a bright windowsill and keep it above about 12°C. Bring a favourite plant in, or root a few cuttings, in late September before nights turn cold. Water sparingly over winter, then take cuttings from the fresh shoots in spring.
Now you can raise coleus for free, read our guide to the best half-hardy annuals for UK gardens for more summer colour to grow alongside it.
Our team produces practical UK gardening guidance from source research, contributor records and established horticultural practice. Editorial standards are overseen by Matt W.
