Skip to content
Growing coleus from seed

Sashay! Shantay! Growing Coleus from Seed

We all love the average, everyday leaf. We know that the green stuff plays an important background role, allowing the pretty colorful stuff to blossom...but what if those leaves decided to steal some of that spotlight for themselves?

That's what's going on with coleus—the divine drag queen of the garden.

You've seen them before. The multi-colored, mint-shaped leaves. Sometimes they're in the houseplant aisle at your favorite nursery; other times, they're outside, outshining exotic garden flowers. Coleus blumei is one of those plants valued primarily for its foliage, and if you grow several varieties together, you're in for one heck of a color mashup—sort of like what would happen if your cat got into RuPaul's makeup bag, and then chirped all over your yard.

Have we sold you on coleus yet? No? Then stick with us. There's more!

Coleus' Backstory

Coleus is native to Southeast Asia. Malaysia, and Australia's more tropical regions. (Australia? Are we talking Priscilla here?) Maybe we need an expert to step in:

"Coleus were discovered in 1853 in the mountains of Java by plant explorer Karl Blume, and until 2006 were named for him (Coleus blumei). Then botanists decided to change the name to the one now used and unpronounceable by most (Solenostemon scutellarioides)."

Dr. Leonard Perry, Extension Professor at the University of Vermont

Did you pick up on that sass? Dr. Perry is on to something. Coleus has more identities than...well, a female impersonator pushing the boundaries of her witness protection program parameters. He even forgot to mention Plectranthus scutellarioides! What's a girl to do when she can't come up with the perfect stage name?

When we refer to Coleus by its Latin name, we'll settle on Coleus blumei. But we're thinking of naming "her" Colleen and calling it a night.

If you try and find out if coleus has medicinal uses, don't be thrown. Also referred to by its genus name, Coleus forskohlii—a.k.a. Plectranthus barbatus—is valued for its active ingredient forskolin (admit it: you did a double-take there, didn't you?) but its foliage lacks C. blumei's pizzazz.

Coleus in the Garden

The coolest thing about coleus is the surprise you get when you start your own plants...especially when you purchase a packet of mixed coleus seeds. The next best thing? Using coleus as a palette of outrageous color, ready to be applied to the canvas that is your fa...uh, garden.

The only glam this stuff lacks is glitter and sequins.

Coleus helps break up solid blocks of green foliage and delivers the most color per square inch of plant material. This is especially useful for container gardens. Here are just a few more ideas:

  • Ditch the bark dust! Plant at the base of lawn trees (especially Japanese maples) to help keep weeds down and interest high.
  • Intersperse with shrubbier, small-leafed landscaping plants to add softness and color, and a variety of leaf sizes and shapes.
  • Use coleus to "paint" your garden with psychedelic, geometric, or fluid designs.

Most people turn to Sunset Magazine for landscaping inspiration. When you're designing your garden with coleus, honey, go on and get yourself an armful of Glamour back issues.

USDA Hardiness Zones: Coleus is a winter hardy, evergreen tender perennial in zones 10-11, but gardeners can grow it as annuals elsewhere. If coleus plants are container-grown and brought indoors for the winter, you can keep them going longer than Darcelle XV's career.

Sunlight Preferences: If you're looking for a plant that loves partial shade, you've found it. Missouri Botanical Garden advises a mix of shade and sun: "Plants grown in too much sun may wilt. Plants grown in too much shade may become leggy." Leggy, for the purposes of gardening, isn't something to strive for.

Your house-lounging coleus plants ("house plants" makes them sound like they're going to clean and cook or something dreadful like that) will need more light than their outdoor counterparts, so set them in a sunny window that gets at least six hours a day.

Moisture Preferences: You don't have to go out and get Jon Waters, or stock cases of San Pellegrino to keep your coleus happy; regular water from the hose or tap works just fine. Just don't let your plants dry out, and don't let them get soggy.

Soil Requirements: Coleus likes rich, well-drained soil. Potted coleus will thrive with any high-quality potting mix.

pH: Aim for a neutral soil with a range between 5.5 to 6.0.

Plant Size: Coleus can be as petite as a half-foot in each dimension, or as grand as three feet tall and wide. Be sure to check your seed packet for specifics, but you can expect the plants from our Rainbow Coleus seed mix to grow in a rounded shape 18" to 30" in height and spread.

Growth Habit: Coleus is a multi-branched plant growing from a single stem. It forms a dense, rounded shape with horizontally-spreading leaves.

Foliage: Coleus plants have the four-sided stems characteristic of all plants related to mints. Serrated, heart-shaped leaves may vary in length (think arrowheads vs. spearheads) but all have a velvety appearance with visible veins. Leaf size varies greatly on each individual plant, and among different varieties.

As for color, hybridization and cultivation have created a gazillion different patterns and hues, but in our Rainbow coleus mix, you're likely to find some or all of the following combinations:

  • Bright green with hot-pink centers
  • Deep burgundy or fuchsia leaves with cream edges
  • Rich green with lemon centers
  • Blood red with pale yellow edges

If you want to mix things up or "space out" different color patterns, try interplanting coleus with some of our more shade-tolerant mints, like peppermint.

Flowers: It might be tempting to let your coleus flower, but it's important to pinch back newly-forming flower spikes. While some less-showy coleus varieties bloom in attractive colors, most have insignificant, tiny blue or white flowers that can't compete with the plants' foliar beauty. Flowering requires a lot of energy, and most coleus plants die when they go to seed.

Pests & Diseases: Think, "I Will Survive." That's coleus; it's relatively pest and disease-resistant, though you'll want to look out for spider mites, aphids, and whiteflies.

Maintenance: You don't need hairspray to encourage coleus' full-bodied, well-kept appearance. Pinch off any flower buds and stray stems to keep it tidy, and feed your plants once a month with a general purpose fertilizer or, for indoor plants, houseplant fertilizer diluted by half.

If your coleus is beginning to look like it needs a makeover or is taking on a scraggly appearance, you can severely cut it back during the growing season (or, where it's a perennial, at the end of the season) and it will bounce back in all its voluptuous glory.

Growing Coleus from Seed

We strongly recommend starting coleus indoors, especially if you're gardening outside Zones 10 to 11. Coleus seeds aren't easy germinators, and they're quite tiny. Discourage stage fright by providing your coleus seeds with smooth, fine soil, consistent moisture, and indoor fluorescent lighting.

Since coleus is a tropical native, cold stratification is neither necessary nor recommended to speed up germination. We do recommend using the freshest coleus seeds and placing 3 to 4 in each pot or cell.

Planting Time: Start your coleus indoors at least 8 weeks before your last frost. You won't want to set your transplants out until the soil has warmed to about 70°F, so any additional "indoor time" will compensate for slow germination, and to allow the plant to gain a foothold on its growth.

Coleus doesn't grow very quickly, which is one of the reasons it makes a great houseplant. But remember, you don't have to wait for it to mature and flower for the big payoff; from the get-go, you get to enjoy the plant's vivid and spectacular foliage.

Days to Germination: 14 to 20 days under optimal conditions (75°F to 80°F ambient temperatures or on a heat mat; use grow lights); sometimes as long as 30 days.

Seed Depth: Coleus needs sunlight to germinate. Scatter or gently press seeds on the surface of a fine, damp seedling mix, and water them with a gentle mist.

Spacing: Transplant (or thin) your coleus 16" to 18" apart. Too close, and they can become leggy as they compete for available light, and if they're given some breathing room as they grow, they'll fill in nicely. If you do happen to get your hands on a dwarf variety, you can reduce the spacing.

Is Coleus Toxic to People and Pets? doesn't list coleus among their list of plants toxic to people, but according to the ASPCA, coleus' essential oils can cause "vomiting, diarrhea, depression, anorexia, occasionally bloody diarrhea or vomiting." Since they mentioned vomiting twice, be sure to keep your pets away from coleus and from any MAC cosmetics.

Essential oils are concentrated forms of plant extracts, but to be safe, discourage your animals from eating coleus leaves. As long as they don't consume them, don't worry about exposing your children to coleus. At worst, they'll gain a greater appreciation for diversity, and perhaps some artistic inspiration.

Contact Seed Needs

It's a rare occasion when we can associate "drag" with gardening and keep a cheerful smile on our faces.

The bad drag is what happens when it's time to do some weeding. The worst drag? When you start your garden with nasty, dusty old if they've traveled across a barren wasteland wedged in the tire tread of an old bus, or journeyed from Tijuana to Twin Peaks in David Duchovny's bra cup. It's essential to store plant seeds in the right environment, which is what we do—and we rotate out our stock so that the seeds we ship to you are as fresh as they get.

If you want inspiration for your garden, bookmark our blog! When you're ready to let your garden "turn the party," contact us at Seed Needs to order seeds for dramatic ornamentals, nutritious vegetables, and health-enhancing herbs.
Older Post
Newer Post