OCCNPS guest author Dan Songster highlights Woolly Bluecurls as the native plant of the month.

Trichostema lanatum-Woolly Bluecurls

• Type: Evergreen Shrub
• Light: Full sun but can take a touch of afternoon shade inland
• Soil: Well drained is best (but debatably adaptable to clay soils)
• Water: Little summer water (if any) after first season
• Common Habitat: Dry rocky slopes, canyons, and washes in desert scrub communities in southwest

Woolly Bluecurls probably need no introduction to many native gardeners. It is a highly prized medium-sized shrub, a perfect fit for many of our home gardens because it is not too big and not too small. It reaches around three to four feet tall and wide. The fact that this is an astoundingly lovely plant in almost every way adds to its appeal. (If you think it looks a bit like Rosemary when not in flower, one of the common names for Trichostema lanatum is Romero, which is a Spanish name for Rosemary.)

Personally, I think this is one of the most alluring and lovely flower/foliage combinations in California gardens. Its shiny, lush, needlelike green foliage is in definite contrast with many of the gray or gray green leaves of its chaparral companion plants. Of course, what draws our attention is its long bloom of purple-blue colored inflorescences, clothed in small hairs giving them a distinctly fuzzy look. Long, curled stamens protrude from the flowers, adding to their delightful appearance. The flowers are well loved by bees, hummingbirds, butterflies, and as one can imagine, a favorite of native gardeners.

Beautiful Scent

And oh, my! It certainly has a one of a kind scent: sweet, somehow resinous–lovely to enjoy either in the garden or when brought indoors as a bouquet where their signature spikes last for well over a week.

This hardy, drought-tolerant native was also important to indigenous Americans, who used almost all parts of the plant for medicinal uses, especially for stomach ailments. Indeed, it became so important that it was used as a currency at times. Tea made from sprigs of Woolly Bluecurls is also extremely tasty, with a soothing, calming effect. The edible flowers can also be used as a garnish on cakes, desserts, etc.

Planting Tips

Try doing something to slightly change the structure of your soil if it is clay (like most of our suburban home gardens). Working in light gravel and decomposed granite into the top few inches of soil seems to help us at Golden West College Native Garden, and if you get things right, it is actually a pretty fast-growing plant. We have plants that are more than six years old and still going. Please avoid incorporating wood products into the soil. Planting should be done in fall to help avoid the need for watering much in the warmer summer months when soil temperatures are high and root rot fungus pathogens are active.

Maintenance

When out of flower, this plant can be leggy with weak branches, so tipping or pinching when the plants are young, encourages a denser, more strongly structured plant. That same pinching back should be done every winter, after it starts to put out new growth to keep it compact and full of those breathtaking deep purple to blue flowers during its spring and summer bloom time.

Lifespan

When older plants become thinner and in decline, rejuvenation attempts that depend on cutting back to old wood to stimulate new growth (coppicing)-simply do not work. Once a plant begins to die, its fate is pretty much sealed. In some lucky gardens after dead or dying plants are removed, seedlings are happily discovered. But in most gardens, new plants are needed to replace the old and they are often replanted every three to five years.

There is legitimate concern over this plant being short-lived. Yes, it has a reputation for being difficult to grow and easy to kill. Some say it needs perfect drainage, no summer water, and a lot of luck. Some have said that to avoid disappointment, lower your expectations and use it as an annual (or biannual). But are these views reflecting the character of this charming plant or just a response to our planting it in clay soils, out of season, and either not giving it enough water to start or too much once established? There is considerable debate about how to grow this plant!

Watering

Most experts agree that watering Woolly Bluecurls in summer can be risky. You may have to, especially in the first year of its life. When establishing young plants, (hopefully in the fall), it’s important to keep them well watered, but make sure to reduce the frequency of the irrigation as they send down their roots. In their second year, only water infrequently. Well-draining soil makes success easier. Many gardener’s experiences show that a key to having healthy plants is making sure they get plenty of water in the winter months so that summer watering needs are greatly reduced.

More Information

For more photos and great information about this plant, consider reading through these very different viewpoints of this wonderful though sometimes confounding native plant, each makes a point of addressing the issue of watering from different angles:

Eric America, in his LA Native Plant Source blog, writes Woollyblue Curse.

Dr. Constance M. Vadheim wrote a very comprehensive look at this plant in Mother Nature’s Backyard.

Lee Gordon of the San Diego Chapter of CNPS has some counter intuitive ideas about growing this plant.

Hybrid

There is a hybrid that is more forgiving of clay soils and garden treatment. It is called ‘Midnight Magic’ and is a hybrid of Trichostema lanatum and the rare Mexican species, Trichostema purpusii. It lacks the silvery hairs on the flower buds of Trichostema lanatum (which gives it the name “Woolly” Bluecurls) and it is a bit more purplish, but what it gains is a more compact habit, a better garden tolerance and longevity, rarely seen with Woolly Bluecurls.

Your Woolly Bluecurls Experience

What has been your experience growing Woolly Bluecurls? Have you found this plant challenging or easy to grow in your garden? Write us back and share your experience with us.