How to Grow Coleus Plants

  • 01 of 04

    How to Grow Coleus Plants

    Coleus plant
    Ron Evans/ Photolibrary/ Getty Images

    Overview

    Coleus plants, made popular as a Victorian bedding plants, made a huge comeback in the 1990s and shows no sign of fading back into anonymity. Why should it? Coleus plants give us all season color, in full sun or shade and everything in between. They are the ultimate low maintenance plant.

    Coleus are tender tropical plants, native to areas bordering the equator. They love the heat, but will happily grow as annuals in just about any garden.

    Description

    • Foliage : Coleus are in the Lamiaceae,...MORE or mint, family and have the familiar square stems and opposite leaves. However the foliage offers a great deal of variety, with some ruffled, others elongated, and an endless combination of colors and markings.
    • Flowers: The tall, thin stalks of flowers are usually pruned off before they bloom, to keep the plant’s energy going toward producing a bushy plant. Since the modern sun coleus types do not grow true to seed, the incidental flowers are not missed.

    Botanical Name:

    Solenostemon scutellarioides
    cvs. (Pronounced sol-en-oh-STEM-on scoot-el-lar-ee-OY-deez)

    Common Names:

    Coleus

    Hardiness Zones

    These tropical plants are only hardy in USDA zone 11, but they are fast growing annuals and can even be grown as houseplants.

    Light Exposure

    Light exposure depends on the variety. The old fashioned seed-grown coleus do best in
    , but the newer vegetatively cultivated varieties have their best color if grown in full sun.

    However it also depends on your climate. If you live in a hot, dry area, all types will need some shade, especially in the afternoon. In cooler, shorter season areas, the shade coleus will need more sun exposure to help them warm up.

    Mature Size

    There are miniature coleus varieties that only grow a few inches tall and others that can grow several feet. In fact, coleus are often trained into standards. To do this, you would either need to be in Zone 11 or have somewhere to overwinter your plants indoors.

    Bloom Period:

    Plants will try to bloom intermittently throughout the growing season, but as mentioned, the flower stalks are usually trimmed off.

    Growing Tips

    Soil: Coleus are said to prefer a neutral to slightly alkaline soil pH, but I haven’t had problems in my slightly acidic soil. I think as long as there is plenty of organic matter, you should be fine.

    Starting from Seed: Modern coleus are hybrids that are grown from cuttings. You can still find seed of the older, shade tolerant varieties. Start seeds meant for the garden indoors, about 8 - 10 weeks before your last frost date. If you are growing them as houseplants, you can start seed anytime.

    Planting: Coleus is not at all frost tolerant. Don’t rush to get your plants in the ground. Wait until temperatures remain reliably above 60 F., before you move them out in the garden.

    Caring for Coleus:

    Water: Although coleus love heat, they also need a moist soil. The soil should not remain wet all the time, but long dry spells will slow the plants’ growth and the leaves will start to turn brown around the edges.

    Mulching will help the soil retain moisture longer, but I have read that cedar mulch can be toxic to coleus. I haven’t tried it myself, so I can’t really say.

    Fertilizer: You’ll get the best color from your coleus leaves if you go easy on the fertilizer. If you have rich soil, you may not need to feed at all. If not, use a balanced fertilizer at half strength monthly.

    Maintenance:

    To get full, bushy plants,
    with the plants are about 6 in. tall. You can do this a few more times, if you like, but once the plants start sending up flower stalks, you’ll be pinching out the stalks and getting the same results as pinching the tips.

    Other than keeping your plants trimmed, the only real maintenance required is ensuring they get plenty of water. Coleus in containers may need watering twice a day.

    Winter Care

    Coleus turns to mush with the first freezing temperatures. If you want to save plants for next season, you have a couple of options.
    1. You can lift and pot up the whole plant and bring it indoors. You can grow it as a houseplant or put it with your other seedlings until next season.
    2. You can take stem cuttings and grow smaller plants indoors.

    Pests and Problems:

    Pests: The biggest outdoor pests are groundhogs and young rabbits. If you can protect your plants early in the season, there are usually other things these animals prefer to eat during the summer and they will leave your coleus alone.

    If you are growing your plants indoors, watch out for scale, whitefly and, especially, mealybugs.

    DIseases: Coleus plants are not usually bothered by diseases, unless the weather turns cool and damp. If that happens, expect to see signs of fungal diseases like mildew.

    Design Tips:

    It’s hard t go wrong with coleus. I have seen large quilt-like plantings of just assorted coleus that looked luscious. They also mix well in borders and containers. You can match the leaves with flowers that echo their color or with colors that complement them.

    Most coleus are a good size for the front of the border and they look best with planted in groups. One use I’m particularly fond of is circling my mailbox with them. They look great, require minimal care out there, and they don’t attract a lot of stinging insects.

    Suggested Varieties:

    I’m not going to even try to suggest varieties. New names (possible for the same plant) appear every year and giving you suggestions would be like sending you on a futile treasure hunt.

    I haven’t found a bad variety. Just be sure to check the label for whether they prefer sun or shade and the expected height. Then indulge and enjoy yourself.

    Continue to 2 of 4 below.
  • 02 of 04

    Coleus as Accent Plants

    Coleus Used as Bedding Plants
    You'll find a coleus color to complement any plant. © Marie Iannotti

    Using a single variety of coleus en mass makes a bold statement and is a great way to bring other colors to life.

    Continue to 3 of 4 below.
  • 03 of 04

    Coleus Make Perfect Container Plants

    Container Coleus
    Coleus grow well in the confines of a container. © Marie Iannotti

    Coleus plants work well in containers, whether mixed with other plants or by themselves. You will need to pinch them back occasionally, to get their size in check.

    Continue to 4 of 4 below.
  • 04 of 04

    Create a Coleus Tapestry

    Coleus Varieties
    Most coleus plants took good when planted together. © Marie Iannotti

    The colors of coleus plants all seem to work together. You can create an entire garden with just coleus and it will be in full color all season.