Perovskia

Perovskia atriplicifolia is usually ignored by deer

Perovskia atriplicifolia

Russian sage (Perovskia atriplicifolia) is a deciduous woody perennial or subshrub with strongly scented gray-green leaves, silvery gray mostly upright stems, and masses of tiny lavender-blue to deep blue flowers on tall spikes from summer through fall.

A fine-textured plant two or three feet tall and wide with an open, airy habit, perovskia is content in full sun with only occasional deep summer watering.  It thrives in almost any soil type, including clay, but must have decent drainage; it sulks and rots where drainage is poor, especially in rainy winters.

Native to rocky steppes of southwestern and central Asia from Afghanistan to Tibet, perovskia accepts both heat and cold and is exceptionally long blooming.  Flowers appear along with lavenders, sages, achilleas, and monkeyflowers, then continue on, to the great delight of bees and butterflies, long after most companion plants have settled into end-of-summer dormancy.  In my garden plants are completely ignored by deer, undoubtedly because of the pungent fragrance of brushed, trampled, or nibbled leaves.

Perovskia atriplicifolia filigrans

Perovskia atriplicifolia ‘Filigran’

Perovskia flowers only on new growth, so plants should be cut back before the next flowering season.  Pruning is key to success with this otherwise easy and adaptable plant. If you don’t cut back, flowers will be sparse.  If you cut back too little, plants may be lax and floppy.  If you cut back too early, plants may die.  It seems best to wait until new growth begins to appear in spring, then cut back to six inches or a foot above the ground.

Some seed-grown plants are said to sucker ferociously, gradually taking over large swaths of adjacent territory.  While one could control rampant spread by chopping out suckers as they appear, it’s easier to plant only cultivars known for little suckering.  ‘Blue Spires’ is a vigorous grower, to four feet tall and wide, with deep blue flowers.  ‘Lacy Blue’ is compact, a foot and a half to two feet tall and wide, with lavender-blue flowers.

Hesperaloe

Hesperaloe parviflora

Hesperaloe parviflora

Hesperaloe parviflora is a handsome architectural plant, as effective singly in large pots as in mass plantings geometrically arranged in the ground.  It is equally pleasing in a naturalistic mixture of succulents, grasses, or other dry-garden plants.

An evergreen plant with long, narrow, gracefully arching foliage, hesperaloe grows three to four feet tall and spreads six or more feet wide by rosettes so closely spaced that they seem to be part of the same plant.  The leathery dark green leaves are spineless with distinctive white threadlike fibers along the margins.  Sprays of pink or pinkish coral summer flowers on tall stalks open in succession from the bottom up, stunning combined with the large, round, bluish gray-green fruits.  Hummingbirds compete aggressively for the flowers if the deer don’t get them first.

I am not sure how much water hesperaloe truly requires or can tolerate.  I grow mine in full sun in large containers filled with commercial cactus mix, where they seem to appreciate watering every week or so in high summer.  In the ground they are said to need little to no supplemental water, but I cannot attest to that.

Too much or too little water – or crowded roots as the potted plants expand – could explain the surprising lack of flowers on my plants after six successful blooming seasons.  I watch every spring for emerging flower stalks, and in their seventh year they did not appear.  I have taken the opportunity to divide the plants and repot in new soil.  We shall see what next summer brings.

There are other hesperaloes in the nursery trade.  Hesperaloe tenuifolia, grassy hesperaloe, is smaller, three feet tall and wide, with even narrower leaves and white or pink-tinged white flowers.  H. funifera, giant hesperaloe, is much larger, four to six feet tall and wide, with upright rather than arching foliage and creamy white or greenish white flowers on stalks ten feet tall.  H. parviflora is sometimes offered as cultivars with yellow or red flowers. All hesperaloes are tough, clean, no-maintenance plants known for their tolerance of both heat and cold.

 

 

 

Salvias

Salvia officinalis (Garden Sage) in bloom with Origanum vulagare 'Aureum' (Oregano).

Salvia officinalis with oregano in background

There are sages (Salvia) for almost any garden.  Annuals, perennials, or shrubs; low and spreading to tall and upright; sun or shade loving; moist or dry soils or anywhere in between.  If you are unsure what a particular sage needs, look it up or consult your nursery professional before adding it to your garden.

One of the most reliable low-water sages for full sun is Cleveland sage (Salvia clevelandii), and one of the best varieties is ‘Winifred Gilman’.  The spikes of bright lavender-blue to purple flowers in early summer are memorable, especially against the silvery gray aromatic leaves.

Salvia leucophylla (Purple Sage) with smaller leaves in summer, silver gray foliage

Salvia leucophylla

Topping out at three or more feet tall and wide, Cleveland sage will thrive with little care for many years.  Bees, butterflies, and hummingbirds love it and deer ignore it.  Native to southern California, this sage needs good to excellent drainage and, in inland locations, seems to prefer, but doesn’t require, a deep soaking monthly in the hottest weeks of the year.  As with many summer-dry plants, a really dry winter or spring will result in loss or shriveling of leaves if no supplemental water is provided. But the plant probably won’t die – leaf drop is a drought response that conserves moisture.

You can trim Cleveland sage back after flowering or take stems for arrangements during bloom, but don’t cut into old wood.  This sage, like many other shrubby perennials, responds well to frequent but gentle trimming as you would lavender or rosemary.

There are many other beautiful sages for the summer-dry garden. White sage, Salvia apiana, is four to five feet tall and wide with fragrant, woolly, almost white gray leaves and white flowers tinged with lavender in spring.  Native to southern California and Baja California, it likes sun and good drainage and needs little to no summer water.  In my garden it sheds many leaves in response to drought, but retains enough of its stunning white foliage to capture attention at any time of year.

Purple sage (Salvia leucophylla) is a long-lived shrub three to five feet tall and wide with wrinkled, silvery gray leaves and pale purple flowers flowers in spring.  Native to southern California, it thrives in full sun with no summer water once established.

Salvia semiatrata (Bicolor Sage) flower detail

Salvia semiatrata

Sonoma sage (Salvia sonomensis) is a mat-forming creeping or trailing evergreen perennial a few inches to a foot tall and spreading three or more feet wide.  Native to California in coastal mountains and Sierra foothills on dry slopes, in chaparral, or in open woodland, this lovely low sage prefers light shade and little or no summer water.  Branches root as they travel across the ground and cascade nicely over walls, the softly textured gray-green aromatic leaves inviting touch. Spikes of medium blue to blue-violet flowers on leafless stems cover the plant from late spring into summer.

Sonoma sage is one of those plants that simply won’t tolerate poor drainage, fertilizers, or more than the slightest summer irrigation.  Give this sage a fast-draining spot on a slope or a mound of rocky soil and resist the urge to “help” it through the dry summer months.  Old plants may get woody and bare in the center, but robust new growth and a slightly mounding habit give the overall effect of continuous cover in lightly tended further reaches of the garden.

Salvia apiana (Bee Sage, California White Sage) California native perennial shrub with silver gray leaves

Salvia apiana

Other drought-tolerant shrubby sages include the long-blooming autumn sages (Salvia greggii), flowers usually red, but many other colors available, and Salvia muelleri (rich dark purple flowers).  S. greggii is about three feet tall and wide; S. muelleri is usually somewhat smaller. Both have diminutive green leaves, very different from the larger gray and grayish white leaved sages.  These sages look best with occasional deep watering in summer, though they will survive without it.  Both can be cut back fairly hard to renew.  Some afternoon shade is beneficial in the hottest locations.

Armeria

California native plant garden with Armeria maritima and Pacific Coast hybrid Irises groundcover lawn substitute.

California native plant garden with Armeria maritima edging a walkway

Sea pink or sea thrift (Armeria maritima) was once more commonly found on “drought-tolerant” plant lists than it is today.  Gardeners who were led to plant it no doubt discovered that it just doesn’t thrive without summer water or afternoon shade except right along the coast.

Sea pink is nonetheless perfect for small gardens or small garden areas where a little summer water can be spared.  Its densely hummocky cushions of evergreen grassy leaves are six inches tall and spread to about a foot wide.  Pink or sometimes white flowers cover the plant from late spring to early summer.

Armeria maritima (Thrift, Sea Pink)

Armeria maritima

Native to coastal areas of northern Europe and the Mediterranean, sea pink is also found in western North and South America.  It prefers good drainage and grows well in sandy or rocky soils as well as in clay.  Use it in rock gardens, in fast-draining containers, or between paving stones in close-up areas where you want a colorful accent.  It is best in part shade inland, full sun along the coast.  The subspecies californica is native to central and north coastal California and is present but uncommon along the south coast.

Achilleas

Achillea 'Moonshine' (Yarrow) Yellow flowering in perennial border

Achillea ‘Moonshine’

Achillea millefolium is a variable perennial, with one kind or another found throughout temperate regions of North America, Europe, Asia.

California has several native kinds of A. millefolium, but the most widely available and commonly planted achilleas, such as the canary yellow ‘Moonshine’ or golden yellow ‘Coronation Gold’, are named hybrids or selections of other species or of plants originating elsewhere.  You may have to seek out the lovely long-lived white- to pink-flowered native achilleas at native plant sales or nurseries that specialize in California natives.

Achillea millefolium 'Island Pink' (Yarrow) in meadow garden

Achillea millefolium ‘Island Pink’, a selected form from the Channel Islands off the coast of California

Achilleas have lacy, finely divided, aromatic, green to gray-green leaves and small daisy-like flowers in compact flat-topped clusters.  Grown in full sun, plants form dense mats six inches to a foot or so tall with masses of flowers on stalks a foot to three feet tall, showy for months in late spring through summer. Blooming can be prolonged into fall by removing spent flowers before they go to seed.

Easy, vigorous, and adaptable, achilleas spread by underground rhizomes, less so by seed, and may be considered invasive in orderly gardens.  Dig deeply, divide, and replant if clumps begin to spread beyond where you want them to grow.  Plants are better behaved with restricted summer watering, though occasional water will improve their appearance in inland areas.

Achilleas make a fine accent or harmonizer and are especially effective in meadow gardens with mounding or spiky grasses or mixed with other perennials. Named cultivars of Achillea millefolium come in a wide range of colors that change subtly with age. Mid-season flowers feature a pleasing combination of varying shades of white, pink, salmon, lilac, orange, crimson, or purplish red, turning buff-colored and then tawny brown as seeds mature.

Flowers are irresistible to butterflies and attractive in both fresh and dried arrangements.  Birds feed on the foliage in winter.  Seemingly undeterred by the rather strong fragrance of the leaves, deer often browse the flowers.

Irises

Pacific Coast Iris 'Copper' flowering in garden with Euphorbia dulcus 'Chameleon'

Pacific Coast iris ‘Copper’ flowering in garden with Euphorbia dulcis ‘Chameleon’

Plants that are dormant or not actively growing during the hottest months are well adapted to summer-dry climates, including many California natives.  Irises, both native and not, are a beautiful choice.

Pacific Coast Iris douglasiana (Douglas Iris) hybrid; California native plant in flower

Iris douglasiana hybrid

Douglas iris (Iris douglasiana) forms an upright clump of sword-shaped or grasslike green leaves, mounding and spreading with age by underground rhizomes.  Flowers are blue-violet, deep purple, or occasionally white, often two or three on each upright stem in late winter to mid-spring.  Native to coastal California and Oregon, this Pacific Coast iris happily tolerates summer dryness in sun near the coast or inland in part shade.  Most leaves will die back in summer but return with fall rains.  Deer ignore this plant and its many named varieties.

One of the most garden-tolerant and easily grown named Pacific Coast irises is ‘Canyon Snow’, with bright white flowers with golden yellow markings at the base of each petal.  Wide-spreading clumps of glossy green leaves are covered with flowers on foot-tall stems in early spring.  Plant in late fall, when new growth starts, usually after the first rains.  Good to excellent drainage is essential; best massed on hillsides or planted on earth mounds or in raised beds.

Pacific Coast iris 'Canyon Snow' and Erigeron

Pacific Coast iris ‘Canyon Snow’ with Erigeron

Bearded irises are another great choice for summer-dry climates, though they are not native to California.  They do benefit from dividing occasionally, at least every four or five years, but they thrive with little or no supplemental watering, even during droughts.  They may not bloom as heavily without winter rains, but they return with vigor when the drought subsides.

Bearded irises are particularly long lived. A small group of old-fashioned yellow-flowered plants have persisted in my garden since I arrived, thirty-five years ago, without dividing and with no supplemental water.  Another bearded iris, with deep purple flowers, I found here the same year, distributed randomly all over the property.  I have gathered them together in one eye-popping display, dividing occasionally but otherwise providing no water and no care.

Lavenders

Lavender 'Provence' in xeriscape drought tolerant garden with grass Stipa gigantea.

Masses of Lavandula ‘Provence’ draw the eye toward a pot and distant sculpture

Lavenders are so at home in California that it’s hard to believe they’re not native here.

Lavenders have green to grayish green or silvery gray, narrow, softly toothed or smooth margined aromatic leaves and upright stems of tubular lavender, purple, pink, or white flowers. There are many species and dozens of named varieties in the trade.

The best known and most widely grown is English lavender (Lavandula angustifolia), a woody perennial subshrub, two to three feet tall and four feet wide, with long, narrow, silvery gray, softly downy leaves and airy spikes of pale lavender flowers in summer.

Lavandula angustifolia 'Hidcote' (Lavender) flowering with orange poppies in drought tolerant garden

Lavandula angustifolia ‘Hidcote’

Most English lavenders available today are cultivated varieties. ‘Hidcote’ is smaller than the species, one to two feet tall and wide, with rich blue-purple flowers. ‘Hidcote Pink’ has pink flowers. ‘Munstead’ is a dense and rounded shrub, 18 inches tall by two feet wide, with lavender-blue flowers and gray-green, smooth margined leaves.

A vastly different lavender, commonly available in nurseries today, is Spanish lavender (Lavandula stoechas).  This is not your grandmother’s lavender.  It is much chunkier in bloom, way more “look at me” than other lavenders that blend subtly into garden compositions.

Spanish lavender, sometimes called French lavender, has downy gray leaves and blooms from spring to fall in warm climates.  The tiny purple flowers are borne on cone-shaped heads topped by outrageously prominent feathery pink to purple bracts.

There are many named varieties of Spanish lavender, including ‘Otto Quast’, one to two feet tall by two to three feet wide, with tiny dark purple flowers and pinkish purple bracts, and ‘Alba’ with creamy white flowers.

Lavandula x intermedia supposedly has the common name of lavandin, but no one I know calls it that.  This plant has broader leaves than most lavenders and bears flowers on long stems from summer to fall.  The lavandin variety ‘Grosso’ is two to three feet tall and wide, with unusually fat flowering heads and dark violet-blue flowers. ‘Provence’ bears lavender-blue flowers on long stems.

Lavandula (Lavender) river as hillside groundcover with ornamental grasses and blue serpentine rocks.

A river of lavender accented by ornamental grasses and blue serpentine boulders

French lavender (Lavandula dentata) is three feet tall by four feet wide, with narrow green leaves, toothed on the margins, and compact heads of pale lavender flowers on short stems. ‘Goodwin Creek Grey’ is a fine-looking hybrid of French lavender, two feet by three feet, with exceptionally silvery leaves and grayish lavender flowers.

Lavenders naturally become woody and rangy over their otherwise long lives.  If you want to keep them dense and mounding, you should treat these shrubs as kitchen herbs, which some, but not all, of them are. Cut plants back the first year after flowering.  Continue to “harvest” every year, cutting back up to a third of new growth for maximum flowering and to maintain the mounding habit.  Replace plants that become lanky or unkempt, usually after four or five years.

Plant in full sun, provide decent drainage, don’t overwater in summer, and don’t fertilize.

Bees, butterflies, and hummingbirds are attracted to lavenders, while deer generally avoid them.