How to Plant, Grow, and Care for Salvia Sonomensis

Xeriscaping is a form of landscaping that requires little to no water. As you might guess, it’s hard to find a ground cover plant that will suit this sort of environment. But I do have one excellent choice to offer: Salvia sonomensis, or Sonoma sage.

Indigenous to parts of California, Sonoma sage forms a dense mat of grey-green leaves. When it flowers, spikes rise from within and erupt in lovely blue-violet blossoms. It has a light sage scent and can tolerate long periods without moisture.

Ready to learn more about this sage species? Let’s get to it!

What is Salvia Sonomensis?

Salvia sonomensis, commonly known as Sonoma sage or creeping sage, is a low-growing, perennial ground cover. Belonging to the mint family (Lamiaceae), this hardy plant thrives in well-drained soils and full sun to partial shade.

It is valued for its aromatic, gray-green foliage and clusters of lavender to blue flowers, which bloom in spring and early summer, attracting bees, butterflies, and other pollinators.

As a drought-tolerant species, Salvia sonomensis is often used in xeriscaping and erosion control, making it an excellent choice for sustainable landscaping. Its compact, spreading growth habit also makes it ideal for stabilizing slopes or adding texture to garden beds.

Native Area

As I mentioned above, Sonoma sage is indigenous to California, like its popular plant cousin, Salvia mellifera (black sage). Also called creeping sage, this perennial is common in foothill and mountain regions. Considered a chapparal plant, it can be grown outside its native environment as well.

Many sages grow throughout California, but this one has a distinct natural habitat. It can be found in coast ranges from Santa Barbara to San Diego. It’s also found in the Sonoma County region and parts of Napa County, as well as northern oak woodland areas.

The largest habitat for this plant is along the Sierra Nevada mountain range in the Yellow Pine forest. There, it grows on southwest-facing slopes below 6000 feet, in foothills and slopes above the central valley region.

All these regions, including the coast ranges this salvia grows in share similar weather conditions. They are arid, but often have nighttime humidity. The summers in Napa county, for instance, are hot but not extreme, topping 90-95°F (32-35°C) but seldom going over 100°F (38°C). Winters rarely drop below 45°F (7°C) for over a few weeks, and there is seldom snow.

Characteristics

Sonoma sage’s leaves are long spearpoints of silvery-green color. Lightly scented like most sages, its aroma acts as a pest repellent. When it flowers, it produces a tall stalk upon which slender, trumpet-like blooms form. Sonoma sage blossoms are often purplish-blue, but some cultivars bloom true purple or white.

Salvia sonomensis does not grow much taller than eight inches. But its flower stalks can hit double that height while in bloom, giving a dual-layered look. What it lacks in height, it makes up for in width. This plant can easily spread in the wild coast ranges, with some plants reaching nearly 15 feet in width. Their deer-resistant nature keeps them alive too!

Varieties

There are quite a few cultivars of creeping sage (Salvia sonomensis). While its natural form is stunning on its own, these cultivars have varying flower colors. Some are bred for even better drought resistance.

Let’s talk about a few of the most popular cultivars, as well as an extremely popular hybrid!

Salvia sonomensis ‘John Farmar-Bowers’

This salvia has the same grey-green foliage as its kin, but one dramatic difference. Instead of blue flowers on its stalks, it produces a creamy white colored bloom. A bed made up of this cultivar with other blue or violet-bloomed varieties is lovely.

Salvia sonomensis ‘Fremont’s Carpet’

This fragrant, evergreen perennial is most common in northern California. Its flowers bloom in the spring, and tend towards the purple spectrum. Low in height, it will spread out to cover large swaths of space. Its aroma is quite appealing when sun-warmed.

Salvia sonomensis ‘Hobbit Toes’

‘Hobbit Toes’ is a compact growing form. Its leaves are pale green and are covered in fine white hairs. This gives them a grey-silver appearance. This foliage forms a mat along the ground from which vivid deep violet flowers appear. It prefers a little light afternoon shade.

Salvia sonomensis x mellifera, ‘Dara’s Choice’

‘Dara’s Choice’ is named after the horticulturist who developed it, Dara Emery. A hybrid of Salvia sonomensis with Salvia mellifera, it grows to reach heights of 18″ tall. The average spread is four to six feet in width. Three- to four-inch long leaves are pale green on top with whitish undersides. This hybrid’s flower colors are blue-purple and also form on spikes. Developed in Santa Barbara, it thrives in a coastal environment.

Planting

To plant Salvia sonomensis, choose a site with well-draining soil and full sun to partial shade, as it thrives in these conditions. Begin by preparing the soil by loosening it and removing any weeds or debris. While it tolerates poor soils, adding compost or organic matter can improve establishment.

Dig a hole slightly larger than the plant’s root ball, ensuring the crown sits at ground level. Place the plant in the hole, backfill with soil, and press gently to eliminate air pockets. Water thoroughly after planting to help the roots settle.

Space plants about 18–24 inches apart to allow for their spreading growth habit. Once established, this drought-tolerant sage requires minimal watering, making it ideal for low-maintenance gardens. Mulching around the base can help retain moisture and suppress weeds, but avoid covering the crown to prevent rot.

How to Grow

Sonoma sage is a tough plant that handles its own needs more often than not. It’s one of the easiest plants to care for and maintain. But it does have a few preferences to consider. Let’s talk about those.

Light

In coastal areas where the temperatures are cooler, Salvia sonomensis should always be in full sun. The same is true in the foothills or low mountain areas below 6000 feet, which mimic its natural environment. It flowers best with at least eight hours of direct sunlight per day.

Water

When established, this perennial is extremely drought-resistant. After all, it grows wild in hilly portions of California. These regions seldom receive measurable rain during the summer. At most, they have a little dew that accumulates overnight.

But young Salvia sonomensis plants do need more water. New plants should be watered at least twice a week to develop their deep root systems. Avoid wetting down the foliage. Instead, use drip irrigation or water at the plant’s base.

Older plants need at most one light watering session per week, and no watering if it has rained. Mulching around the plant’s base will help prevent moisture evaporation. During excessive heat, they will tolerate regular summer water in the early morning. This simulates the overnight dew which the plants receive.

Avoid overwatering. Sages are perfect for xeriscaping because of their low water needs, though they will tolerate regular summer water. Too much water can cause dieback due to fungal root rots. When in doubt, skip watering.

Soil

In the wild, creeping sage often is found in coast ranges with gabbro soil types, like the Sierra Nevadas, northern oak woodland areas, and Yellow Pine forest. These soils are comprised of decomposing igneous rock, and often hold little water.

Outside of their natural environment, gabbro soils are uncommon. We can simulate them to a degree by providing extremely well-draining soils. Sandier soil types are preferred for growing Salvia sonomensis. Avoid heavy clay soils, as the roots cannot easily penetrate it.

If you cannot provide a sandy soil blend, opt for a potting mix which is perlite-heavy to promote as much drainage as possible.

Temperature

When the heat index spikes up above 90°F on a regular basis, providing afternoon shade for your Salvia sonomensis is wise. If it’s occasionally too hot, your plants can handle it. Weeks of extreme weather can cause difficulties, though.

Fertilizing

Fertilizer is generally unnecessary. It is tolerant of nutrient-deficient soils and needs little to sustain itself. This tough little ground cover is determined to live against all odds! Fertilizers may even cause poor performance.

Maintenance

Like its relative white sage, Salvia sonomensis is not tolerant of heavy pruning. Never remove more than a quarter to a third of this plant’s height at any time.

Most pruning will be to remove spent flower stalks. It’s recommended that you allow the flowers to dry completely and drop their seeds first. They will self-seed and remain perennial in their placement. Once the seeds have dropped, clip the stems, which grow at a height to match the rest of the plant.

Propagation

Propagation of Sonoma sage is best via cuttings or seed.

The seeds should be scratched lightly on a sheet of sandpaper to scar their hard surfaces. Once scratched, soak them in water for 24-48 hours. Shallowly plant them within one week of soaking, with just a fine coating of soil over top.

Cuttings should be from young, vigorous stems growing on your Salvia sonomensis. A rooting hormone is recommended to encourage fast root development. Place in moist sand or perlite, keeping the potting medium damp until one to two inches of roots form. You can then repot into prepared soil.

Common Problems

Tough and resilient, few problems plague this creeping sage. We’ll discuss those rare problems below and how to handle them.

Growing Problems

Overwatering can cause dieback. Most often, this is directly caused by fungi that develop in overly wet soil. Like many drought-resistant plants, Salvia sonomensis is at risk of fungal root rots. It’s best to err on the side of too little water than too much, though they will tolerate regular summer water. In fact, if the weather is moderate, you may not need to water at all!

Remember to avoid planting in heavy clay soils, which inhibit root growth. You can try to amend heavy clay soils, but it may be better to plant yours in a container with potting soil amended with perlite. Full sun is also essential for this plant.

Pests

The sage oils that the Salvia sonomensis plant naturally produces in its leaves repel pests. Very few pests find this or other sages appetizing. It’s also a deer-resistant plant.

In very rare situations, you may find a few aphids on your plant. This is most true after the plant has recently had a watering. The hollow, woody stems act as moisture storage for the plant’s leaves. After a watering, aphids will pierce the leaf surfaces to drink this sap. A quick spritz of insecticidal soap eliminates these quickly.

What the plant does draw in are beneficial insects. Salvia sonomensis flowers are natural lures for all manner of butterflies, bees, etcetera. Pollinators find this plant to be irresistible. If you’re trying to develop a pollinator garden, this is a perfect choice!

Diseases

Outside of fungal-origin root rot, the only plant disease that is common is powdery mildew. It can be hard to spot on the grey-green foliage, but at the same time, it rarely causes severe damage.

Frequently Asked Questions