Santolina

Santolina chamaecyparissus:  Workhorse of the Drought Tolerant Garden
               
                    By Sonoma County Master Gardener Sandy Metzger

A friend insists on calling it St. Helena. I have yet to find an historical connection; perhaps it’s a memory-relationship strategy. Just say ‘Santolina’ because the second half of its botanical name, chamaecyparissus, is nearly impossible to pronounce (or spell). Nursery staff will know what you mean.

 Gardening books do not extol the virtues or rave about this plant; they must be objective: just the facts. So I will! It’s an outstanding plant for Sonoma County gardens and the reason that we have selected it as one of our Top Plants!

Its common name is Lavender cotton, of which it is neither. You’ll recognize it when you see it and smell it. It is not a California native but instead was introduced in about 1952 from the Mediterranean. It has naturalized below 1700’ in Riverside, Los Angeles, Monterey, and Sonoma counties (but not invasively).

Santolina loves Sonoma County! They were made for each other. Our county has the perfect conditions in which Santolina thrives:  rainy winters, hot, dry summers, and full sun. It was born and raised in sandy, rocky, infertile soils but will tolerate garden loam or well-amended clay.  The soil needs to be well-drained. Santolina requires infrequent water once established and is drought-tolerant. You will kill it if you over-water it! It does not like wet, humid conditions in the summer and will develop fungus.

Its form is a rounded, dense, silvery gray mound up to 2’ high and 2’ wide. It has a compact cousin ‘Nana’ which grows to only about a foot. In mid-summer bright yellow ½” button-like flower heads appear on stems above the foliage. They seem to last forever, but eventually fade to tan. Because Santolina is an evergreen, its foliage persists through winter and will look lovely on the dreariest of days. No book mentions this, but the flower-stems are excellent in dried arrangements and on wreaths.

S. rosmarinifolia is another cousin, but with bright green foliage and softer yellow flower heads. S. pinnata, subsp. tomentosa, has mid-green foliage with creamy white flower heads. Both require similar growing conditions.

Rub the foliage between your fingers. The fragrance is described as aromatic, or musty. To me, “pungent” seems most appropriate. The deer must think so as well because they generally avoid it. A deer-resistant, drought-tolerant sub-shrub—what could be better?

Santolina’s many fine qualities give it a wide variety of uses in the garden. It can be massed by itself for a dramatic effect. It can be planted in a mixed shrub or perennial border with lavender, salvias, rosemary, rock roses, senecio, artemisia, or buckwheats. It mixes well with herbs such as thyme, sage, oregano and nepeta. It can be used in rock gardens or as a low-clipped hedge. And it’s always mentioned in xeriscape books for low desert or Mediterranean garden designs.

Does it have any problems or challenges? Yes: over-watering! Also, it needs to be pruned back severely in late winter or spring to keep it from getting too leggy, woody or splitting apart in the middle. Similar to lavender, it is not long-lived and may need to be replaced every five years or so.

You can actually propagate your own new plants by taking semi-ripe cuttings in the fall, potting them up in a quality nursery planting mix, and providing bottom heat. You can sow seed in a cold frame in autumn or spring. I have also noticed they will occasionally “layer” themselves:  when a branch bends down and touches soil, it will establish roots to start another plant. It means you can do this yourself and easily create your own new Santolinas!

If you are considering reducing or eliminating your lawn or installing a water-efficient garden, Santolina is one plant you must include. Get it established and then barely water it! Really.