Santolina (Lavender Cotton)
Santolina chamaecyparissus from the Mediterranean Basin is commonly called lavender cotton, a confusing name with no connection to either lavender or cotton. The Latin derivation translates to “holy flax” in English, but that, too, is obscure. It makes most sense to use the botanical name as the common name, as most gardeners do.
Similar to lavender or sage, santolina foliage has a pungent or musty aroma, easily distinguished when leaves are bruised. Scent and taste deter deer and other browsing animals.
- Santolina thrives in Sonoma County’s rainy winters and hot, dry summers, but it tends to be short-lived and often needs to be replaced after 5 or 6 years.
- Considered an evergreen sub-shrub for its lower woody stems, santolina forms a rounded, dense, silvery gray mound of soft foliage up to 2 ft. high and wide.
- Native to sandy, rocky, infertile soils, it tolerates garden loam or well-amended clay as long as it is well-drained. Plants require ample moisture for a year after planting.
- Once established, santolina requires only infrequent watering; it is completely drought-tolerant, though looser growing, in shaded sites. Over-watering in summer will stimulate fungal growth that can be fatal.
- Shrubs prefer full sun but grow quite easily in nearly full shade where flowering is diminished.
- Some gardeners object to the ½ in. yellow, button-like, summer flowers on tall stems that stand above the blue-gray foliage and remove them.
- Other gardeners shear plants regularly as a low hedge along walkways or garden borders and never see flowers emerge.
- Still others combine santolina with a low-growing teucrium (germander) and sculpt them once or twice a year into a classic, interwoven knot garden.
- Santolina can also be used in rock gardens or mixed with other low-water perennials and herbs.
- Plants may be propagated by taking stem cuttings in the fall, potting them up in a quality nursery planting mix, and providing bottom heat over winter.
- Plants will occasionally layer themselves when a branch bends down and touches moist soil. After roots develop, the branch can be snipped off and replanted elsewhere to start another plant.
To Shear or Not To Shear
Shearing can present a challenge if plants are ignored for several years and allowed to develop thick, woody lower stems.
- Annual removal of flowering stems may include shearing or simple deadheading.
- Annual shearing or sculpting to maintain a hedge or knot garden keeps plants low.
- Pruning every one or two years involves cutting mounds back severely in late winter or spring into hard wood, but cuts must be made just above lower buds.
- Woody stems will not survive if pruned below obvious buds.
- Pruning every 1-2 years maintains a neat outline and keeps santolina from becoming too leggy, woody, or from splitting apart in the middle.
Santolina chamaecyparissus is most often grown for a silvery gray element in gardens and landscapes. Gray-green, evergreen foliage is nearly needle-like, similar to lavender, and highly pungent.
- A compact cultivar, ‘Nana,’ grows to only about 1 ft.
- ‘Pretty Carol’ and ‘Lemon Queen’ with creamy yellow flowers are each a little taller.
- Santolina rosmarinifolia is another species with a similar growth habit but with needle-like, softer, bright green foliage. Flower heads on this species are brighter yellow. The cultivar ‘Morning Mist’ has a compact habit.