This drought-tolerant ground cover is frost hardy down to zero degrees – Orange County Register

There is an extremely drought tolerant ground cover that is hardy down to zero degrees known as lavender cotton (Santolina chamaecyparissus). It is rarely seen but is a pleasant garden oddity. It features gray foliage with a cottony consistency and profusions of small yellow spherical flowers that will remind you of acacia trees. This plant has a misleading name as it is not botanically related to either lavender or cotton, but belongs to the daisy family, which is closely related to chamomile. You can also find green-leaved Santolina species. One of them has pale yellow petals and goes by the cultivar name Lemon Queen. There is also a more compact Nana variety.

Some gardeners choose to forgo flowering lavender cotton when deciding to use it as a low-growing hedge, a garden design element for which it is better suited than any other plant. Santolina hedges can also be formed into letters to spell words. A few years ago, on a roadside slope near the entrance to Jerusalem, I saw “Bruchim Habaim” (meaning “Welcome”) in Hebrew letters formed from Santolina hedges.

Maintained under 30cm tall and regularly sheared and nested, santolina leaves make a wonderful formal border to a bed of colorful ornamental sage (Salvia spp.). Sage blooms in red, pink, lavender, blue, and purple, and each of these colors stands out brilliantly when surrounded by silvery santolina. Speaking of sages, The New Book of Salvias: Sages for Every Garden (Timber Press, 2008) is an excellent book to give as a Valentine’s Day gift to the serious gardener in your life. Written by Betsy Clebsch, find detailed cultural information for growing sages, many of which are suited to shade and most of which have a significant degree of drought tolerance.

Native to western and central Europe from Portugal to Yugoslavia, Santolina derives from two Latin words: sanctus linum, meaning sacred flax. Its sanctity comes from the supposed healing properties of its flowers and leaves. I say “allegedly” because this plant has not proven to be as medicinally effective as was previously thought. When researching the properties of almost every plant, a large number of medicinal uses are invariably listed. In the past, a doctor also had to be a botanist, because medicines were limited to remedies that were obtained from parts of plants – whether leaves, flowers, bark or roots.

So why is the famous healing power of so many plants, as described in literature since the Middle Ages and antiquity, no longer recognized? I believe there are two reasons for this. First, when the only medicine available to humans came from plants, people were more familiar with how to use them – and the processes required to extract their beneficial ingredients – for healing purposes. Second, the growing conditions that would result in a high concentration of the healing chemical constituents in a plant may no longer be known, conditions critical to growing medicinal plants for their intended effects. You would need to know how much sun or shade and what type of soil is best to increase the potency of a particular species, as well as at what time in its life cycle, what time of year and what time of day they do best corresponding plant parts can be harvested.