Is Flamethrower Coleus a Perennial or an Annual?

Flamethrower coleus is one of the most popular ornamental plants grown today for its vividly colored multi-hued foliage. Its brilliant leaves display eye-catching combinations of burgundy lime green, orange, yellow, and more to create a dazzling foliage display in gardens and containers. But a key question many home gardeners have is whether flamethrower coleus is actually a perennial plant or an annual. Knowing the lifespan of this beautiful coleus variety will help guide how and where you can best utilize it in your landscape. In this article, we’ll take an in-depth look at whether flamethrower coleus is a perennial or an annual.

Overview of Flamethrower Coleus

Flamethrower coleus belongs to the plant genus Solenostemon and species scutellarioides. It also goes by its botanical name Plectranthus scutellarioides. This tropical plant is native to regions like Africa, Asia, and Australia. Flamethrower coleus is part of a popular series of coleus bred by Ball Horticultural Company, prized for its dramatically multicolored foliage.

What makes flamethrower coleus so valued is its kaleidoscope of colorful leaves. The foliage displays varying combinations of deep burgundy bright lime green vibrant orange, sunny yellow, pinkish-red, and more. The serrated leaves have a distinctly ruffled, jagged edge. Mature flamethrower coleus reaches about 18-24 inches tall and wide in an upright, mounding form.

Flamethrower coleus thrives in warm weather and does best in zones 10-11. It requires at least 4 hours of direct sunlight per day. Too much shade will cause its vibrant leaf colors to fade. Well-drained, fertile soil is ideal to keep it happy. Its insignificant flowers mean this plant is grown solely for its sensational foliage.

Is Flamethrower Coleus a Perennial?

Flamethrower coleus is primarily grown as an annual plant in most regions. It can only be considered a short-lived perennial in frost-free climates where temperatures stay above 40°F year-round. In zones 10-11, flamethrower coleus may overwinter and return the following spring. Everywhere else, it’s generally cultivated as an annual.

One reason flamethrower coleus acts as an annual is because it cannot tolerate any frost. Temperatures dipping just below freezing will damage or kill the plant. Its native tropical habitat is frost-free all year, so flamethrower coleus has no inborn tolerance for cold.

Even in zone 10 or 11, flamethrower coleus will thrive during hot summer months but tends to decline in winter. Flowering reduces its vigor, and the foliage may thin out or lose its striking colors in cooler winter weather. Each spring, gardeners in warm climates must evaluate if overwintered plants are vigorous enough to revive or if new plants should be started.

Growing Flamethrower Coleus as an Annual

For most gardeners, the best way to enjoy flamethrower coleus is to grow it as a fast and flashy annual. Here are some tips:

• Start seeds indoors 8-10 weeks before your last expected frost date. Provide bright light and temperatures around 70°F for optimal germination.

• Transplant seedlings or purchased plants outdoors after all danger of frost has passed. Gradually acclimate plants to sunlight first.

• Space plants 12-15 inches apart in garden beds and borders. Ensure the soil is enriched with compost and drains well.

• Pinch back shoot tips periodically to encourage bushy, compact growth. This also prolongs the plant’s life.

• Water frequently, about 1-2 inches per week. Don’t let the soil dry out completely.

• Fertilize every 2-3 weeks with a balanced liquid fertilizer during the growing season.

• Remove spent flowers to promote more leaves and sustain plant vigor.

• In frost-prone areas, start new flamethrower coleus plants each spring for peak performance. Plants usually only last one season.

Using Flamethrower Coleus in Gardens and Containers

The blaze of color from flamethrower coleus makes it a real standout in gardens as well as containers. Here are some ways to showcase it:

In Garden Beds & Borders

• Plant en masse for a bold color statement. Or mix with flowers, foliage plants, and grasses for exciting contrast. Use as edging along paths or the front of beds.

In Containers & Planters

• A great “thriller” plant for container combos. Pair with trailing plants like ivy or verbena. Also shines solo in pots and window boxes.

In Hanging Baskets

• Cascades beautifully over basket edges. Mix with calibrachoa, petunias, or other trailing annuals.

Indoors

• Grow in a sunny window as a houseplant. Provides unique indoor color all winter. Needs at least 4 hours of direct sunlight daily.

Overwintering Flamethrower Coleus Indoors

Gardeners in frost-prone zones can overwinter flamethrower coleus indoors as a houseplant. This involves digging up a plant before the first fall frost and providing ideal indoor growing conditions. Here are some tips:

• Choose the healthiest, most vigorous plants to overwinter. Avoid flowering plants.

• In late summer, prune the plant by 1/3 to reduce stress on roots during transition.

• Dig up the plant and repot it into a container just slightly larger than the root ball.

• Provide at least 4 hours of direct sunlight from a south or west-facing window. Supplement with grow lights.

• Maintain indoor temperatures between 60-80°F. Keep away from cold drafts.

• Allow the soil to partially dry out between waterings. Water less frequently in winter.

• Resume fertilizing every 2-3 weeks in spring when new growth emerges.

• Transplant back outdoors after the frost danger has passed next year.

Overwintering gives gardeners in cold climates a chance to enjoy flamethrower coleus for more than one season. But it requires diligent care to keep plants healthy indoors through winter.

Common Problems with Flamethrower Coleus

When grown as an annual, flamethrower coleus is relatively trouble-free. However, it can encounter a few problems to watch for:

• Sunscald – Leaves turn brown or bleach tan from too much direct sun. Provide afternoon shade in hot climates.

• Fading leaf color – Warm weather, fertilizer, and ample sun needed to maintain richest foliage hues.

• Leggy growth – Increase sunlight exposure. Pinch back regularly to encourage bushiness.

• Root rot – Avoid overwatering. Improve drainage if leaves wilt and plants decline.

• Mealybugs & whitefly – Check leaf undersides and treat early before pests spread.

• Deer browsing – Typically not bothered by deer. Use physical barriers if needed.

With proper care, preventative measures, and ideal growing conditions, these problems can generally be avoided. Flamethrower coleus is relatively unfussy when grown as an annual.

Final Thoughts on Flamethrower Coleus as Perennial vs. Annual

To summarize key points in this article:

• Flamethrower coleus is primarily used as an annual in all zones except 10 and 11. It cannot tolerate frost or cold temperatures below 40°F.

• In USDA zones 10-11 only, flamethrower coleus may return each spring and act as a short-lived perennial. Winter performance is often weak.

• For most gardeners, flamethrower coleus will thrive for one growing season and be replaced each spring for peak performance.

• Grow it in beds, borders, containers, and hanging baskets to take advantage of its long summer bloom period as an annual.

• Overwintering indoors is possible but requires diligent care. Plants often decline after one season.

• Start new plants each year for the biggest visual impact from flamethrower coleus’ stunning multicolored foliage.