As winter approaches, a longing for snow may occupy your mind if, like me, you grew up with snowy winters, moved to Southern California, and now experience nostalgia for fluffy white blanket over the earth.
The consolation is that you can at least bring plants with white or silvery foliage into your garden, many of which thrive in our climate. Nearly all of them are perennials, so that your horticultural winter wonderland could be on display throughout the year.
How about a garden devoted exclusively to plants with foliage of this kind? Now that would be a sight to see.
There are three genera – Senecio, Centaurea, and Artemisia – that are especially well-known for silvery foliage. Most are low-growing species, usually perennials between one and four feet tall. They are generically known as dusty millers, a moniker that conjures up millers whose profession was grinding wheat into flour, which left them covered with white dust. The most popular dusty miller is a bedding plant with pointed, finely cut foliage (Senecio viravira). Another with blunt or rounded leaf tips and serrations (Senecio cineraria) is also widely seen. Both sport small white or yellow daisies that are nothing special. Some gardeners remove these flowers as soon as they appear in order to direct the plant’s energy into leaf production alone.
Velvet centaurea (Centaurea cineraria/gymnocarpa) has the most eye-catching flowers among the dusty millers. They are violet-purple and are borne abundantly on and off throughout the year. While reaching three feet or taller, the growth habit of this species is rather compact and so it is eminently possible and even advisable to train a linear planting of it into a distinctive hedge.
Dusty millers possess three drought-tolerant characteristics: succulence, heat resistance, and hairiness. In truth, they are more semi-succulent than succulent, since leaves do not have a leathery texture. But the true test of a plant’s claim to succulence is the ease with which it can be propagated from cuttings. Here I can testify that 4-6 inch shoot terminals detached from dusty millers in the fall or early spring will easily root in any well-drained soil. And succulence, of course, speaks to a plant’s ability to retain moisture and stay hydrated when temperatures rise. Actually, many succulents have white or silver foliage, woolly senecio (Senecio haworthii) being the purest white among them.
As for heat resistance, the grayish-white cast of dusty miller foliage does an excellent job of reflecting the sun’s rays and thus contributes to keeping the plant cool and less water needy in hot weather. Finally, the fuzzy hair that covers dusty miller leaves traps moisture that, in glabrous or smooth-leaved plants, is typically lost into the atmosphere in rapid fashion during the process of transpiration – by which water moves from roots to leaves to the outside air. Not only does this fuzz protect against water loss, but it provides insulation on cold nights as well. Antelope Valley (Palmdale and Lancaster) residents have no fear: Dusty millers will survive your winters too.
Artemisias are famous for the alcoholic beverages made from them: absinthe, Pernod and vermouth. Wormwood (Artemisia absinthium) also makes a wonderful silvery hedge. Leaves are very finely cut, if floppier than those on dusty millers. This is the plant from which vermouth was originally made. Vermouth (verm = worm in German) was given this name on account of its power to heal an upset stomach which, two centuries ago, was typically ascribed to the presence of intestinal worms.
Artemisia var. Powis Castle is a silvery mound that reaches 3 feet in height while sandhill sage (Artemisa pycnocephala), native to Southern California beaches, is a two-foot tall mound, while its David’s Choice cultivar stays under a foot. Artemisia versicolor var. Sea Foam is a burgeoning delight that comes at you in foamy waves. Finally, California sagebrush (Artemisia californica) has finely cut grey foliage and pops up on undisturbed hillsides and canyons throughout the Los Angeles area; Canyon Grey, a prostrate cultivar, is widely planted.
As long as we are on the subject of natives, keep California white sage (Salvia apiana) in mind. It is being poached to extinction due to its vaunted properties as a smudge stick for spiritual cleansing. Planting it thus becomes an act of conservation. Not to be forgotten are the whitish-gray Dudleyas, those star-shaped succulent beauties that you still find clinging to slopes along canyon and wilderness roads, here and there, throughout the greater Los Angeles area and which are available in most California native plant nurseries.
As for hanging baskets, Dichondra var. Silver Falls displays long chains of silvery gray, heart-shaped leaves. As for ground cover, there is an ever-popular sturdy grey-leafed gazania with yellow flowers that barely ever needs watering. It has a trailing growth habit and thus will also hang out of a flower box or spill over a block wall. Finally, when it comes to trees, nothing can match the weeping silvery blue presence of weeping myall (Acacia pendula).
If you would like to add a vegetable to your silvery selections, do so with an artichoke plant or two. Aside from its edibility, this is a plant whose gigantic leaves with deep indentations make a striking ornamental statement. For another aesthetic sensation, leave the artichoke’s unopened flower buds (which we normally eat) alone and soon, when they open, you will see what may be the largest purple flowers in the plant kingdom. These can be cut and used as dramatic accents in vase arrangements.
California native of the week: Dougas Kent, author of “Foraging Southern California” (Adventure Publications, 2020), e-mailed me to recommend the California black walnut for mention here. This is a symmetrically domed tree growing up to 50 feet tall. It is widely encountered in canyons and on hillsides throughout Southern California from the Santa Ana to the Santa Monica Mountains. It hugs the slopes between Ventura Boulevard and Mulholland Drive Drive – along Coldwater Canyon and Beverly Glen Boulevards, for example – at the southern edge of the San Fernando Valley. Kent instructs the preparation of its tasty walnut meats (the edible portion) as follows: “The best way to split the shells is to boil the walnuts for 15 minutes after removing the hulls. They break open at the seam fairly easily. The meat is then picked out. I was using a nutcracker before, but I would always get bits of the shells mixed with the meat, which made eating them uncomfortable. The taste of these walnuts is buttery and phenomenal; they are loaded with oil.”
If you have a white, silver, or gray-leafed plant that you think deserves wider recognition, please write me about it at joshua@perfectplants.com. Your questions and comments concerning any gardening practice or problem are always welcome, as are your photos which, for possible publication, should be taken with a horizontal orientation
