Ornamental · Lamiaceae
Salvia (Annual)
Salvia splendens
Give scarlet sage full sun and soil that stays moist, and it rewards you with flower spikes from summer clear to frost.
Full sun
Every 3–7 days
50–90°F · 10–32°C
USDA 10–11
Overview
If you have never grown annual salvia before, you are in good hands, because scarlet sage is one of the friendliest bedding plants to start with. Those tall spikes of fire-red flowers that brighten summer borders come from a member of the mint family, and although it is a tender perennial that only survives winter in zones 10 and 11, most gardeners simply grow it as a warm-season annual and set out fresh plants each spring.
The best part for a beginner is how much color you get for so little worry. Blooms begin in early summer and keep opening right up to the first frost, and the bright tubular flowers bring hummingbirds and bees to your garden. Plants stay neat and compact, somewhere between 8 to 36 inches (20 to 91 cm) tall depending on which type you choose, so there is a salvia to tuck into beds, along an edge, or into a pot on the patio.
Do not let a shaky start worry you, because this plant is quick to bounce back. It really only asks for sun, warmth, and soil that never bakes bone dry, and it flowers freely in return. Snip off the faded spikes now and then and the plant keeps blooming, so even a forgotten watering or an uneven trim is easy to recover from.
Care
The short version: give scarlet sage full sun with maybe a touch of afternoon shade, keep the soil evenly moist so it never dries out hard, mix in a slow-release feed when you plant, and pinch off spent spikes now and then to keep the flowers coming.
Light
Scarlet sage blooms its best in full sun, though a little afternoon shade is welcome where summers turn fierce. Give it too little light and the plant tends to stretch tall and flop, with far fewer flower spikes to show for it, so a bright, open spot really does pay you back.
Water
This salvia likes its soil kept evenly moist, since it is not a plant that shrugs off drought. Check the top inch of soil and water once it starts to dry, watering more often for plants in pots or during a hot spell. If it does dry out on you, the blooms are the first thing to suffer, but a good drink usually brings it back.
Soil
Plant scarlet sage in well-drained loam with some compost or other organic matter worked in, though it is happy enough in ordinary garden soil too. It is not fussy about pH and settles in comfortably anywhere from 6.0 to 8.0.
Temperature
Warmth is what makes this plant happy, roughly 50°F to 90°F (10°C to 32°C), and a frost will end it outright. Hold off on planting until both the soil and the air have warmed up, and it will thank you for the patience.
Humidity
Everyday outdoor humidity suits scarlet sage just fine, so there is no target to fuss over. What matters far more is airflow, because crowded plants sitting in still air are the ones that invite powdery mildew, so leave a little breathing room between them.
Feeding
Mix a slow-release fertilizer made for annuals into the soil at planting time, then top it up with a light feed here and there as the season goes on. That gentle, steady supply keeps new flower spikes coming without pushing the soft, floppy growth that a heavy hand can cause.
Pruning
Keep deadheading the faded spikes all through summer and the plant will keep answering with fresh bloom. Should it grow leggy after a big flush of flowers, do not be afraid to shear it back, since a trim brings on tighter, bushier growth.
Size & spacing
Depending on the type, plants reach 8 to 36 inches (20 to 91 cm) tall and spread 8 to 18 inch (20 to 46 cm) wide. Give each one a bit of elbow room so air can move around the leaves, which is your simplest defense against mildew.
When to plant
Salvia loves warmth and has no patience for frost, so timing is simply a matter of waiting for it to be warm enough. Start seeds indoors in late winter or early spring, then move the young plants outside only once the last frost has passed and the ground feels warm. From there the flower spikes carry you from early summer until the cold finally closes the season, and there is no rush to get ahead of the weather.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6 to 8 weeks before the last spring frost; do not cover seed as light aids germination
- Plant: After the last frost when soil and air have warmed
- Harvest: Summer to frost (roughly June until first fall frost)
Hardiness
USDA hardiness zones: 10–11
Temperature: down to -1°C
Troubleshooting
Most bumps with salvia show up early, either while the seedlings are tiny or when plants sit too close together in still air. The good news is that catching a problem early usually makes it an easy fix, so look over the signs below, find the match, and step in while it still helps.
Young seedlings flop over and rot right at the soil
That sudden collapse is damping-off, a soilborne fungus that thrives in cold, wet starting mix and pinches tender stems shut where they meet the soil. It feels discouraging, but recovery is simple: clear away the seedlings that went down, let the mix dry a little between waterings, and open up the air around the tray. Sow a fresh round in sterile mix and clean pots, keep everything warm, and the next batch usually comes through fine.
Fix:
- Discard affected seedlings
- Improve air circulation and let the surface dry between waterings
- Use sterile mix and clean containers for resowing
Plants wilt suddenly and rot at the base in hot, wet ground
When a plant wilts even though the soil is still damp and the base is turning to rot, the cause is likely southern blight or southern bacterial wilt, both of which strike in hot, waterlogged ground. Sadly there is no bringing an affected plant back, so pull it up and get rid of it to protect the rest. Improve the drainage in that bed, and give susceptible annuals a different home next season.
Fix:
- Remove and destroy affected plants
- Improve drainage
- Avoid replanting susceptible annuals in the same spot
A powdery white coating creeping over leaves and stems
A soft white dust on the foliage is powdery mildew, and it moves in when plants are packed together and the air hangs still. Ease the crowding, snip away the worst of the coated leaves, and keep water off the foliage in the late afternoon. A sunny spot with room to breathe stops it from settling back in.
Fix:
- Increase spacing and airflow
- Remove badly affected foliage
- Avoid overhead watering late in the day
Curled new shoots, a sticky film, and specks of insects
Warped shoots and a sticky sheen usually mean aphids, whiteflies, or spider mites are feeding on the tender new growth and leaving honeydew behind. Knock them loose with a hard jet of water first, then treat whatever hangs on with insecticidal soap. Keep the plant evenly watered and let a few beneficial insects move in, and the next round rarely amounts to much.
Fix:
- Rinse plants with a strong spray of water
- Apply insecticidal soap to affected areas
- Encourage beneficial insects
Toxicity
Here is a reassuring note for pet owners and parents: scarlet sage is non-toxic. The ASPCA lists it as safe for both cats and dogs, and there is no toxin in it that would harm other animals, livestock, or a curious child. You can plant it wherever the family gathers and not give it a second thought.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats are safe around scarlet sage, which sits on the ASPCA's non-toxic list. A cat that eats a big mouthful might bring it back up, as with any plant, but nothing here will actually poison it.
Dogs None
Dogs are welcome near this salvia with no risk at all, since the ASPCA counts it non-toxic to them. A dog that wolfs down a lot of leaves may get a brief upset tummy, the same thing that happens with most greenery.
Horses Safe
There is nothing poisonous here for horses, so a border or pasture planting poses no grazing worry.
Rabbits Safe
Rabbits can nibble the leaves and flowers without coming to harm. As with any fresh green, bring it into their diet slowly so their stomach can adjust.
Livestock Safe
Cattle, goats, and sheep run no toxic risk should they graze on this salvia.
Birds Safe
Birds have nothing to fear from the plant, and pollinators drop by the flowers all season. Backyard chickens can peck at it without any trouble.
People Safe
Annual scarlet sage is not poisonous to people, and it is grown for its flowers rather than the table. There is no cause for alarm if a child picks or tastes a bit of it.
Varieties
Named salvias run into the many, but only a handful show up on garden center benches season after season. Those are the ones worth getting to know first.
Bonfire
Bonfire holds its scarlet spikes evenly across upright plants that stand about 26 inches tall.
Salsa Series
The Salsa Series keeps things compact at 12 to 14 inches in scarlet and mixed shades, and it holds up well through the muggy heat of the Southeast.
Vista Group
Dwarf and quick to bloom, the Vista Group opens early and comes in a broad sweep of colors.
Salvia farinacea (mealycup sage)
Mealycup sage, or Salvia farinacea, sends up blue-to-violet or white spikes on clumps of 1 to 2 foot and is often grown as an annual as well.
How to propagate
Making more salvia is refreshingly simple, and there is no wrong way to begin. You can sow a fresh batch from a seed packet each spring, or take cuttings to keep a plant you love going through the winter.
SeedModerate
Start indoors 6 to 8 weeks before the last frost; surface sow because light aids germination · Several weeks to germinate and grow on before transplanting after frost
Most gardeners get their start from seed, sown indoors about 6 to 8 weeks before the last frost. Scatter the seed right on the surface and leave it uncovered, because light is what wakes it up. Keep the tray warm and brightly lit, and give it time, the seedlings need several weeks to sprout and fill out before they are ready to head outdoors once frost has passed.
Stem cuttingsModerate
Take softwood cuttings in late summer to overwinter plants indoors · A few weeks to root
Cuttings are how you hold on to a plant you especially like. Take softwood cuttings in late summer, let them root over a few weeks, and keep the young plants going in a bright, cool corner until spring returns.
Myths
The scarlet sage in your flower bed is really the same plant as the psychoactive Salvia divinorum.
They only share a genus, nothing more. The garden annuals, Salvia splendens and Salvia farinacea, are grown purely for their flowers, and neither has any of the properties people associate with Salvia divinorum, so the scarlet sage on your patio is simply a pretty bloomer.
Once salvia settles in, you can let it dry out because it handles drought.
Annual scarlet sage is not a drought-tolerant plant. It blooms best when warm, well-drained soil is kept evenly moist, and the moment it dries out the flower spikes start to fade in a hurry.