‘FlameThrower Salsa Verde’ is a narrow-leaved coleus with bright chartreuse-green foliage, grown for its leaves rather than its flowers.1CAES Field Report. Coleus’ bright foliage performs beautifully in summer landscapes It’s a tender tropical plant, so most gardeners treat it as a summer annual and keep it going all season with warmth, steady moisture and the occasional snip. Light decides how it looks more than anything else you do, because its color shifts depending on how much sun it gets.
How Much Sun Salsa Verde Needs and How Light Changes Its Color
Chartreuse-leaved coleus turn noticeably lighter and more yellow in full sun.2Journal of Environmental Horticulture. Sunlight and Shade Effects on Coleus Leaf Color Perception The reason is that strong light makes many coleus build more red-purple pigment and lose some green.3PubMed. The role of light on foliage colour development in coleus (Solenostemon scutellarioides (L.) Codd) On Salsa Verde, that means the burgundy accents may deepen in sun while the green fades toward yellow. Orange-leaved coleus do the opposite and look richest in shade, so advice for one coleus doesn’t always fit another.4Journal of Environmental Horticulture. Sunlight and Shade Effects on Coleus Leaf Color Perception
Morning sun with afternoon shade gives most gardeners the lime color the plant is sold for. Salsa Verde has been shown off in sunny Southeastern summer trial gardens, so it can handle more sun if you like a brighter, yellower look.5CAES Field Report. Coleus’ bright foliage performs beautifully in summer landscapes
Your plant’s leaves tell you whether the spot is right. Leaves that wash out to pale yellow or show scorched edges are getting too much hot sun. Dull, darker green leaves on stretched stems suggest it wants more light. If you move a potted plant, shift it a few feet at a time, and give it a week or two before judging, because only new leaves will show the change.
Nursery tags and photos show the plant under one set of conditions, so yours may not match the picture. A plant grown in shade at the nursery and planted straight into hot sun can bleach or scorch in the first days, so set it in the sun gradually over a week or so, or start it where it gets only morning sun.
Indoors, a sunny window gives far less light than outdoors, so indoor plants rarely bleach. Turn the pot weekly so the plant grows evenly instead of leaning toward the glass. Containers on hot patios or near walls pick up extra reflected heat, so afternoon shade matters even more there.
Best Soil and Containers
Coleus grows equally well in garden beds and containers.6University of Minnesota Extension. Coleus It likes rich, well-draining soil that stays evenly moist, so mix compost into garden beds before planting.7The Spruce. How to Grow and Care for Coleus Plants It grows best when soil pH is between about 5.3 and 6.3, and growth falls off below about pH 4.7 or above 7.0.8Acta Horticulturae. Influence of substrate pH on coleus growth Very alkaline soil may hold it back.
An inexpensive soil test kit or a local extension office soil test will tell you your pH. If your area has chalky or alkaline soil, growing in pots with fresh potting mix avoids the problem. Don’t try to change the pH for a summer annual unless a test shows it’s well outside the range.
For pots, use a good-quality potting mix.9The Spruce. How to Grow and Care for Coleus Plants Adding about 1 part perlite to 4 parts mix keeps the soil airy so extra water drains away.10Palettblad.com. Soil for coleus – the best mix & how to repot Avoid heavy peat mixes that pack down, and mixes with water-holding gel, because coleus doesn’t want to sit wet.11Palettblad.com. Soil for coleus – the best mix & how to repot
The pot itself needs drainage holes. A pretty pot without them can rot the roots quickly. Salsa Verde grows full by midsummer, so a cramped nursery pot will need moving up.
How Often to Water
Newly planted coleus need watering every day for the first week.12Plant Addicts. Watering Coleus Once the roots settle in, a plant in the ground can often go a few days between waterings, depending on heat and humidity.13Plant Addicts. Watering Coleus
Plants in garden beds that were watered only when the soil got fairly dry still looked just as good as daily-watered plants. They ended up about 15–20% shorter and noticeably narrower, though.14HortTechnology. Landscape Growth and Aesthetic Quality of Coleus Managed with Irrigation Deficits
To know when it’s time, push a finger an inch into the soil; if it’s dry there, water. Wilting at midday in heat may recover by evening, but wilting in the morning usually means the plant needs water, unless the soil is already wet. Water slowly at the base until it runs out the drainage holes. Pots in summer sun may need water daily or even twice a day.
Constantly soggy soil and saucers full of water can rot roots, which also causes wilting. Watering in the morning lets leaves dry, which helps prevent leaf disease. In cool, cloudy spells the plant uses less, so ease off.
Feeding Without Losing Leaf Color
Feeding coleus more nitrogen makes it grow bigger, but at high nitrogen rates the leaf color becomes less intense.15Journal of Plant Nutrition. Optimum N and P rates for greenhouse production of vegetative coleus using constant liquid feed Lightly fed plants were a little smaller but looked just as good because their color was stronger.16Journal of Plant Nutrition. Optimum N and P rates for greenhouse production of vegetative coleus using constant liquid feed Salsa Verde grows poorly if it gets very little phosphorus, but a moderate amount is enough for full growth.17Acta Horticulturae. Influence of phosphorus fertilization on coleus growth
A balanced liquid fertilizer at half the label strength every two to four weeks suits most coleus in pots. In rich, compost-amended garden beds, it may need little or no extra feeding. Organic fertilizers such as insect frass can grow good-looking coleus and wash fewer nutrients out of the pot.18HortTechnology. Black Soldier Fly Frass Supports Plant Growth and Reduces Nitrogen Leaching during Coleus Production
“Balanced” means similar amounts of the three main nutrients listed on the label, a simple choice for a leaf plant. Apply it to damp soil rather than bone-dry soil, which lowers the chance of burning the roots. Slow-release granules mixed into the potting mix at planting are an alternative if you’d rather not feed every few weeks, though you then have less control over how much the plant gets. Reduce feeding as the weather cools and growth slows in autumn.
Large, floppy, faded leaves with fast growth point to too much fertilizer. Small, pale lower leaves and slow growth suggest the plant is hungry.
Pinching and Pruning for a Bushy Plant
Pinching means snipping or nipping off a stem’s growing tip just above a pair of leaves. Two new branches then grow from the spot where the leaves meet the stem.19Horticulture. Pinch Back Coleus for Optimal Growth Trimming new growth also stops stems getting long and keeps the foliage dense.20Plant Addicts. Pruning Coleus
Start when the young plant has three or four sets of leaves. Use your fingertips or clean snips just above a leaf pair, and repeat every few weeks through summer whenever stems start to stretch. Save the healthy pieces you cut, because they can become new plants.
Coleus sends up flower spikes, and the small flowers draw attention away from the leaves.21Horticulture. Pinch Back Coleus for Optimal Growth Removing the spikes lets the plant put that energy into new leaves.22Plant Addicts. Pruning Coleus
If a plant has already gone leggy, cut tall stems back by up to half, keeping some leaves on each. New growth usually appears within a couple of weeks in warm weather. Feed and water as usual afterward to support the regrowth.
Cold, Downy Mildew and Other Problems
Coleus comes from tropical Java and is adapted strictly to warm temperatures.23Plant Physiology and Biochemistry. Differential temperature dependencies of antioxidative enzymes in two contrasting species: Fagus sylvatica and Coleus blumei Plant it out only after nights stay reliably warm, and expect frost to kill it. Cold damage doesn’t need frost, though. Coleus can sulk, stall or drop leaves on cool nights well above freezing, so a plant set out too early may sit still for weeks. A cold snap after planting can leave leaves blackened or limp, and a plant that is badly hit rarely recovers its look. If a late cold night is forecast, bring pots indoors or cover beds overnight with a light cloth, removing it in the morning.
Downy mildew is a leaf disease that causes spotting or browning of the foliage.24Greenhouse Product News. Downy Mildew on Coleus It grows fastest when it’s moist and cool, around 59–68°F.25Greenhouse Product News. Downy Mildew on Coleus In hot, dry weather around 77–86°F it can go quiet inside the plant without dying, and return when it cools.26Greenhouse Product News. Downy Mildew on Coleus Very humid conditions followed by drier air release large numbers of spores.27Acta Horticulturae. Etiology and Environmental Control of Downy Mildew and Root Rot Pathogens in Coleus Production Keeping humidity under about 85% and temperatures above 75°F helps limit outbreaks.28e-GRO Alert. Coleus Disease Disorder Guide No coleus variety tested was resistant, though some were less affected than others.29Acta Horticulturae. Etiology and Environmental Control of Downy Mildew and Root Rot Pathogens in Coleus Production
Look for brown or blotchy leaves and a fuzzy grayish growth under the leaves. Remove and bag affected plants rather than composting them. Space plants for airflow and water at soil level, not over the leaves.
Mealybugs, small white cottony insects, can infest coleus, especially indoors.30Journal of Entomological Science. Performance of Entomopathogenic Fungal-Based Insecticides against the Citrus Mealybug (Hemiptera: Pseudococcidae) on Coleus (Lamiales: Lamiaceae) Plants under Greenhouse Conditions Fungus-based biological sprays did a poor job controlling them.31Journal of Entomological Science. Performance of Entomopathogenic Fungal-Based Insecticides against the Citrus Mealybug (Hemiptera: Pseudococcidae) on Coleus (Lamiales: Lamiaceae) Plants under Greenhouse Conditions Wipe them off with a cotton swab dipped in rubbing alcohol, or discard heavily infested plants.
Growing New Plants From Cuttings
Cuttings rooted in plain peat moss survived poorly, often less than half.32Journal of Bio-Environment Control. Comparison of the Growth of Coleus (Plectranthus scutellarioides) Cuttings in Peatmoss and Perlite Substrates Cuttings in a mix of 1 part peat to 2 parts perlite all survived and grew the most roots.33Journal of Bio-Environment Control. Comparison of the Growth of Coleus (Plectranthus scutellarioides) Cuttings in Peatmoss and Perlite Substrates Keeping cuttings in a moist, humid enclosure also produced far more and longer roots than open air.34HortTechnology. Comparison of Four Systems for Propagation of Coleus by Stem Cuttings A clear bag or covered tray over a perlite-heavy mix gives the best start.
Cut a 3–4 inch shoot just below a leaf pair and strip the lower leaves. Push the stem into moist mix and cover loosely to keep humidity high. Keep it warm and in bright, indirect light. Roots typically form in one to three weeks, and a gentle tug that resists means it has rooted.
Take cuttings from healthy, actively growing stems rather than tired or flowering ones. Take a few more than you need, because some may fail.
Bringing It Indoors for Winter
Let the plant adjust for about a week before moving it fully inside.35Gardening Know How. Winterizing Coleus: How To Overwinter Coleus A week in a garage or laundry room before a warm room eases the change.36Epic Gardening. Winterize Coleus: How to Overwinter Coleus Plants Then place it in bright light such as a south- or west-facing window.37Epic Gardening. Winterize Coleus: How to Overwinter Coleus Plants Water only as needed, since it grows slowly indoors.38Gardening Know How. Winterizing Coleus: How To Overwinter Coleus Plants kept in darker rooms usually survive, but their color looks duller.39Epic Gardening. Winterize Coleus: How to Overwinter Coleus Plants
Bring it in before night temperatures drop toward the 50s °F. Check for pests first so they don’t spread to your houseplants. Expect some leaf drop and stretching, and pinch in late winter. Rooted cuttings take less space than a full plant and replant well in spring.
What to Plant With Salsa Verde
Salsa Verde’s narrow leaves let it fill the role of a small shrub such as golden duranta in a bed.40CAES Field Report. Coleus’ bright foliage performs beautifully in summer landscapes It has been paired with purple gomphrena for a striking display.41CAES Field Report. Coleus’ bright foliage performs beautifully in summer landscapes Chartreuse coleus also contrast sharply with purple heart’s dark purple leaves.42Gardenia. A Long-Lasting Border Idea with Tradescantia and Coleus Dark-leaved shrubs such as elderberry and nandina set off contrasting coleus, and low coleus can cover bare ground around young shrubs.43Plant Addicts. Coleus Companion Plants
Pick companions that also like steady moisture so no plant is stressed. In containers, use Salsa Verde as the tall center with trailing plants at the edge.
Is Coleus Safe for Pets
Coleus is among houseplants whose main effect on pets is an allergic reaction, usually skin irritation from contact.44PubMed Central. Toxicity of House Plants to Pet Animals Keep plants out of reach of chewing pets, and call a vet if your pet shows drooling, vomiting or rash after contact.
Indoors, hang pots or place them on high shelves. Wear gloves when pruning if your own skin is sensitive, and clean up dropped leaves and cuttings that pets might play with.