Step-by-Step Guide to Growing and Caring for Scarlet Sage (Salvia splendens) at Home

Scarlet sage lights up the garden with tall spikes of tubular flowers. While red flowers are the most popular color, new cultivars boast white, purple, and pink flowers. All of these flowers attract dazzling displays of hummingbirds and butterflies. Plus, no matter what color flowers you choose, you’ll end up with a low-maintenance plant. Here we’ll take you through everything you need to know about growing and caring for Scarlet Sage (Salvia splendens) at home including planting, soil considerations, light preferences, feeding, pruning, and over-winter care. 


How to Grow Scarlet Sage (Salvia splendens) – The Essentials

Botanical Name:Salvia splendens
Also Known As:Scarlet sage, red salvia
Hardiness Zones:Can survive winter in zones 9-11, can be grown as an annual in zones 4-8
Flowering Months: May through November
Growing Difficulty:Easy
Type of Plant: Perennial, treated as an annual in cold areas
Light Requirements:Sun to part-shade, prefers at least six hours of sun
Temp & Humidity:Thrives in temperatures between 60-90ºF, cannot survive temperatures below 32ºF
Watering Needs:Water about once a week in the summer and once every two weeks in spring and fall
Soil Preferences:Well-drained; prefers sand or loam
Feeding:Fertilize in the late spring and summer with a fertilizer designed for flowering plants
Growth Expectations:Up to two feet tall and two feet wide

About Salvia splendens

About Salvia splendens

Family, Genus, and Species

Origins and History

Salvia splendens is native to Brazil. While the native form can still be found, gardeners often plant modern cultivars.

Plant breeders have created cultivars of Salvia splendens that look quite different from the original plant. While some of these cultivars have red flowers, others have purple, white, and pink blooms.

Here are some of the most popular Salvia splendens cultivars available today:

  • ‘Alba’
  • ‘Bicolor’
  • ‘Scarlet Pygmy’
  • ‘St. John’s Fire’
  • ‘Violacea’

Scarlet Sage Botanical Characteristics

Scarlet Sage Botanical Characteristics

Scarlet sage plants have tender, square stems that grow up to two and a half feet tall. Many stems combine to form a clumped appearance.

Oppositely arranged leaves adorn the stems. The leaves are ovular or heart-shaped with scalloped edges. These leaves may be anywhere from one to three inches long.

Numerous flowers appear on a tall flower stalk that rises above the plant’s leaves. The flowers are tubular in shape and anywhere from one to two inches long. While they are often red, they may also be white, purple, or pink.

Uses & Benefits of Scarlet Sage

Scarlet sage is an excellent addition to pollinator gardens. Its flowers provide nectar for butterflies, hummingbirds, and bees.

When is Scarlet Sage in Season?

Scarlet sage begins blooming in the late spring or early summer and continues until the first frost. It may bloom throughout the winter in frost-free areas.

Scarlet Sage Growth Expectations

Scarlet Sage Growth Expectations

Plants can grow up to two feet tall and two feet wide. However, if you are growing scarlet sage as an annual it is unlikely to get this big.

Companion Plants for Scarlet Sage

Scarlet sage works well with flowering perennials and annuals of similar heights.


How to Grow Scarlet Sage

How to Grow Scarlet Sage

Choosing a Location

Fortunately, scarlet sage plants aren’t too particular about their location. While they prefer full sun, they can survive in part shade and full shade.

Due to their tall form and dramatic flowers, these salvias make great additions to mixed flower beds as well as borders. Plant a line of these plants and you’ll end up with a brilliant edge along a path or fence.

They also work well as container plants and add dramatic height to mixed planters.

No matter where you plant scarlet sage, you’ll want to check the drainage. If an area appears continually moist, it’s best to choose another location.

What are the Best Times of Year to Plant Scarlet Sage?

The best time to plant scarlet sage is in the spring after the danger of frost has passed. This will allow the plant to become established before the summer heat arrives.

If you live in an area without frost, you can also plant scarlet sage in mid-fall. The cool temperatures will allow plants to establish a strong root system so they can take off the following spring.

Growing Scarlet Sage From Seed vs. Transplanting

Growing Scarlet Sage From Seed vs. Transplanting

It is possible to grow scarlet sage from seed or transplants.

If you’d like to grow these plants from seed, you’ll need to plan ahead. Start seeds indoors about 6-8 weeks before the predicted last frost date. To provide the seedlings with enough light, place them near a sunny window or use a grow light.

Before you plant the seedlings outdoors, make sure to harden them off. This involves placing them outside for a few hours and then a few more hours the next day. Plants will be acclimated to the cold by the time you are ready to plant.

If you are purchasing transplants, wait until the danger of frost has passed. You should harden off these plants before planting them in the ground.

What to Do Before Planting Scarlet Sage

Before you plant scarlet sage, you should inspect the area. Make sure the soil is well-draining and there are no signs of puddling.

If you are planting a mixed flower bed, lay out your plants. Before you plant them, make sure each plant has enough room to grow without becoming crowded.

If you’re incorporating scarlet sage as part of a container planting, make sure the pot has drainage holes.

What’s the Best Soil for Scarlet Sage?

What’s the Best Soil for Scarlet Sage?

Scarlet sage isn’t too particular about soil.

Its ideal soil is a sandy loam, but it can thrive in any well-drained soil. It prefers a soil pH that is neutral to slightly acidic.

How to Plant

If you are planting in the spring, it is important to allow transplants to acclimate to outdoor conditions. Allow potted plants to sit outdoors a few days before you plant them.

Once you’re ready to plant, dig a hole that is a few inches larger than the plant’s root ball. Place the plant in the hole, cover it with soil, and water well.

Light Preferences

Light Preferences

Scarlet sage thrives when it receives at least six hours of bright light each day. However, it can also grow well in part-shade or dappled light.

While plants won’t die in full shade, they won’t thrive. Expect stunted plants and a lackluster flower display.

Temperature & Humidity Preferences

Salvia splendens prefers summer temperatures between 65-90ºF. Lower temperatures will slow plant growth.

Unfortunately, this plant is not frost tolerant. It will die if temperatures fall below 32ºF.


How to Care for Scarlet Sage (Salvia splendens)

How to Care for Scarlet Sage (Salvia splendens)

When and How to Water Scarlet Sage 

Scarlet salvia plants like soil that is moist but not wet.

During the summer, expect to water plants once a week during times of drought. If you receive substantial rain, you can skip watering.

Be aware that scarlet salvia plants are prone to root rot. If the top few inches of soil is wet, there is no need to water.

How, When, and Why to Fertilize

Salvia splendens will benefit from regular fertilization.

To encourage lots of flowers, fertilize once in the late spring with a fertilizer designed for flowering plants. Fertilize once a month in the summer for continuous blooms.

Pruning Scarlet Sage

Pruning Scarlet Sage

Scarlet sage doesn’t require regular pruning but removing dead flowers and stems will keep it tidy.

If you are growing scarlet sage as a perennial, you can prune the plant in late winter. Use a sharp pair of pruning shears to cut the plant back so it is four to six inches tall. This will encourage new growth and flowers.

Propagation

Scarlet sage is easy to propagate via seed and stem cuttings.

Seed

If you’d like to grow new plants from seed, start seeds 6-8 weeks before you want to plant them outside. Keep seeds warm and moist until they germinate. Once seedlings have emerged, provide bright light so the plants can grow.

Stem Cuttings

Since many scarlet sage cultivars are hybrids, seeds won’t produce plants that resemble the parents. You can use stem cuttings to produce plants that are clones of the parent.

To propagate scarlet sage via stem cutting, follow these steps.

  1. Cut a piece of stem that is 4-8 inches long.
  2. Remove any leaves from the bottom two inches of the stem.
  3. Place the cutting in a glass of water so the cut end is submerged. Ensure that no leaves are in the water.
  4. Place the glass and cutting in an area with indirect light.
  5. Change the water every few days.
  6. After a few weeks, you should see roots form. Allow these roots to grow until they are at least half an inch long.
  7. Pot up the cuttings in a container filled with potting mix.

Overwintering Scarlet Sage

Overwintering Scarlet Sage

Scarlet sage can survive the winter in areas that do not receive frost.

If you live in an area that receives only one or two light frosts per year, plants may survive with some help. If frost is forecasted, cover your plant with a piece of frost cloth or bedsheet. Remove the covering the next day.

If you live in an area with cold winters, it’s best to grow scarlet sage as an annual. 

However, you can overwinter it indoors. To do so, dig up the plant and place the root ball in a container. Store the plant in a cool, dark area until spring arrives.

Repotting Plants Grown in Containers

Repotting Plants Grown in Containers

If you’re growing scarlet sage as an annual container plant, you won’t need to repot it. Just make sure you give it enough space to start.

If you’re growing a perennial container plant, you should repot every two or three years. Repot in the late winter or early spring.

When it comes time to repot, remove the root ball from the container and brush off excess soil. Add a few inches of new potting soil, add the plant, and fill with more potting soil.

Deadheading Scarlet Sage

Deadheading will encourage scarlet salvia plants to produce new blooms. You should begin deadheading in early to mid-summer and continue through the fall.

Deadheading involves removing all dead flowers. Since scarlet sage flowers grow on a stalk, you’ll want to remove the whole stalk. Use a pair of sharp shears to cut the flower stalk a few inches from the ground.


Common Scarlet Sage Problems and How to Treat Them

Common Scarlet Sage Problems and How to Treat Them

Fortunately, scarlet sage plants don’t deal with many diseases or pests. Due to a strong odor, they are resistant to rabbits and deer.

The most common problems are powdery mildew and root rot. While these diseases can occur naturally, they are often caused by an improper environment.

Proper plant spacing and at least six hours of sun will help prevent powdery mildew and other foliage fungi. 

Root rot, a fungus that affects roots, is often caused by overwatering or poorly-drained soils. Make sure to only water when the top few inches of soil is dry and use containers with drainage holes.


Essential Tools for Growing Scarlet Sage

Essential Tools for Growing Scarlet Sage

Scarlet sage doesn’t require too many specialized tools, but the following items will be useful:

  • Soaker hose or watering can
  • Pruning shears
  • Perlite or sand
  • Soil probe or moisture meter
  • Mulch, compost, or slow-release fertilizer pellets

Wrapping Up

If you want a low-maintenance yet show-stopping flower, scarlet sage is a great choice.


Growing Scarlet Sage (Salvia splendens) FAQs:

Salvia splendens can grow up to two feet tall and two feet wide.

If you live in zones 9-11, scarlet sage will survive the winter without any additional care. If frost is expected, cover your plant with a piece of frost cloth or bedsheet. Remove the covering once temperatures rise above freezing.

Scarlet sage plants will not survive heavy frosts. If you’d like to save your plants, you can dig them up and bring them inside over the winter.

No, scarlet sage is not invasive.

Yes, scarlet sage is a perennial. However, it is often treated as an annual in cold climates.

Once flowers have died, you should remove entire flower stalks. Use a pair of pruning shears to cut the flower stalk a few inches above the ground.

Scarlet sage will grow in shade, but it prefers part-shade or full sun. If grown in full shade, it will appear stunted.


More Salvia Flower Growing Guides:

For more essential step-by-step guides to growing and caring for Salvia plants at home, please see our in-depth features on Salvia coccinea (Texas Sage), Salvia greggii (Autumn sage), and Salvia nemorosa (Woodland sage).


Author

Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.

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