How to Plant, Grow, and Care for Salvia Guaranitica

Salvia guaranitica is an attractive perennial with cobalt blue flowers and either light green or black calyces. Also known as ‘Black and Blue’, the cultivar belongs to the Salvia genus of evergreen shrubs.

The sometimes pale blue flowers, sometimes deep blue flowers, and pale green leaves to deep green leaves are not only gorgeous, but they are also a pollinator attractant that hummingbirds love. They’re highly pest-resistant perennials that love full sun and bloom from mid-summer to fall.

This salvia received the Royal Horticultural Society Award of Garden Merit! So, pick one up at your local nursery, and let’s learn to grow this purple perennial with dark stems that attract hummingbirds!

What is Salvia Guaranitica?

Black and blue salvia, or Salvia guaranitica ‘Black and Blue’ is also known as blue anise sage, anise-scented sage, Brazilian sage, giant blue sage, sapphire sage, blue ensign, purple splendor, and hummingbird sage. Its lovely flowers and pale green foliage, which smells lovely, are perfect for pollinator gardens and borders.

Native Area

It originates in Brazil, Paraguay, and Northern Argentina. It’s naturalized in Central America, too – namely, Costa Rica.

It thrives in the subtropical and tropical climates of these areas, often growing in open woodlands, forest clearings, and along stream banks.

Characteristics

At the beginning of the blooming period, it has pale blue flowers with a lightly toothed lower lip. Toward the end, the flowers deepen to deep cobalt blue.

This sage is a drought-tolerant perennial as it has moisture-conserving rhizomes. It’s a tall shrub with an anise scent, dark stems, and a running rootstock that forms wide clumps of stems. The stems are covered with ovate dark green leaves and one to two inches long dark blue flowers that sit atop either yellow-green calyces or black calyces. Each green calyx blooms deep blue flowers in mid-summer through autumn. They are sun lovers. that grow up to five feet tall.

Salvia guaranitica belongs to the Lamiaceae family and can be perennial, biennial, annual, evergreen, or herbaceous. It is known for its simple or pinnately lobed, fragrant pale to dark green leaves and two-lipped blue flowers on spikes. It’s quite similar to its cousin, Salvia rhinosinia, with a height up to eight feet tall, and vigorous, and often invasive tubers. Like Salvia guaranitica, its cousin also loves sunny to partial shade areas.

It takes about one to two years to reach its full height. It’s low-maintenance and drought-tolerant, with bloom time from June to frost. Its fragrant foliage and deep blue flowers attract butterflies and birds. Due to its unique characteristics, it makes a perfect xeriscape planting choice to add to your garden’s border.

Planting

Planting Salvia guaranitica is a simple matter of preparing the soil by enriching it with compost. The best time to do this is in spring or early summer. Space more than one salvia 24-36 inches apart to allow for their mature size. Dig a hole slightly larger than the root ball. Remove any plastic around the roots, place the salvia in the hole, and backfill with soil, pressing gently to remove air pockets.

Water thoroughly after planting and maintain consistent moisture until the plant is established. Once growing, Salvia guaranitica is drought-tolerant and requires minimal care.

How to Grow

Blue anise sage is definitely low to no-maintenance when planted in the right conditions. Here’s what it needs to thrive.

Light

Salvia guaranitica requires full sun to partial shade to grow well. Grow in well-lit spot (some light shade is okay), preferably south-facing or west-facing. Avoid north facing, or too much shade if possible.

Water

Salvia guaranitica likes regular watering when it’s getting established. After transplanting, water once or twice a week, especially during the mid-summer. After it is established, it will subsist with very little to no water. Give it at least weekly water during hot weather in severe drought situations or periods with little to no rainfall for the best flower development. While it’s drought-tolerant, that doesn’t mean it can survive on no water at all! In particularly humid regions, stay on the lookout for mildew.

Soil

Salvia guaraniticas love rich, well-drained soil. Avoid poorly drained soils as they can cause root rot. Go for sandy, chalky, and loamy soils with a slightly acidic pH of 5.5-6.5.

Here in North Texas, it does just fine in our heavy clay soil that’s amended with well-rotted compost. To keep the soil’s nutrient content up, refresh it annually with a little more well-rotted compost. Container plants do best with rich, well-draining potting soil that’s refreshed annually in the same way.

Temperature

It’s a winter hardy salvia that grows well in USDA Zone 8-10 and can tolerate heat, even in full sun conditions.

As for frost, in cooler areas, it acts as a tender perennial, dying back when temperatures are consistently below freezing. Before winter, mulch around the base to protect the roots in winter, or bring containers indoors. Overall, for growing conditions, remember where this grows naturally in Costa Rica.

Fertilizer

Only the container-grown Salvia guaranitica benefits from fertilizer. Sprinkled sparsely around the base, a slow-release fertilizer will provide enough nutrition to keep it healthy throughout the year. In-ground salvias should not be fertilized, especially if planted in rich soil.

Maintenance

When your salvia gets too big for its container, it may need to be up-potted. To start, prepare a pot with good drainage holes. Fill the pot with potting soil and lightly compact it. Make sure the pot is slightly bigger than the root ball by about one inch. Dig out the salvia and lightly prune off the root tips to make the root ball more manageable. Use a knife to split the roots into sections. Keep the segments evenly moist, not soggy. Carefully replant into the pot.

Once the flowers fade on the yellow-green calyces in late fall, you can remove spent flower spikes all the way to the ground. Alternatively, you can leave the stems, and dark green leaves will grow again on the remaining woody stems. This provides a habitat for overwintering insects, including beneficial pollinators. Thankfully, whatever you choose, this perennial will return in early spring and should be fully growing in late spring. Blooms don’t need last year’s growth to produce that lovely flower color.

Of course, remove any dead or diseased branches with sharp pruning shears as needed throughout the season.

Propagation

This sage can be propagated through softwood cuttings several weeks after the last spring frost date or semi-ripe cuttings in late spring to mid-summer. Make sure the stem or rhizomes are evenly moist but not overly hydrated, which can cause root rot. Plant them in early autumn in a cool, dark place, leaving a little soil around the root ball. When they grow, move them to a bright, warm spot.

I’ve had success propagating by cuttings in fall, and keeping it in a pot indoors through winter. Then after the last spring frost date, I planted it in late spring. It started blooming in late summer, and many more blooms will come throughout the fall season.

Common Problems

Salvia guaranitica is a low-maintenance type of perennial. Let’s explore some common growing problems you may face while growing it. As for larger mammals, this sage is deer-resistant.

Growing Problems

If your Salvia guaranitica is grown in too much shade, the stems may elongate and fall over. This process is referred to as etiolation and is a sign of the salvia reaching for much-needed sunlight. When you place them in your garden, always keep them in areas with full sun to partial shade. Over-watering can also cause various fungi to develop and can lead to root rot. Therefore, always make sure to grow in well-drained soils.

If you prune heavily at the incorrect time, in the active growth phases of spring, late summer, and early fall, it may suffer and die. But most of the time, it will easily survive an onslaught of issues.

Pests

While Salvia guaranitica is highly pest-resistant, you may notice the following common insects. The leaves are susceptible to whiteflies, aphids, spider mites, and leaf hoppers that can suck on the stem and leaf juices. Use insecticidal soaps, neem oil, and a jet of water to keep them away. However, if you’re planting to attract pollinators, stick with water as your first defense or spray at sunset once the pollinating insects have retreated for the day to allow your treatment to dry on the plant. Do not spray the flowers directly, only the leaf or stem surfaces. You may want to skip it entirely, as black and blue salvia can handle most pest infestations.

Diseases

They can also suffer from downy mildew and powdery mildew due to poorly drained soils and high humidity. The best way to prevent this is by pruning for airflow and removing weeds to promote aeration. Water early in the morning so the leaves and flowers can dry out during the day. Always grow in well-drained soils

Remove the infected foliage if powdery mildew or downy mildew becomes a significant issue.

Frequently Asked Questions