Selecting Tough Plants for Tough Times

There are tough days ahead for gardeners across the country. We are already suffering through record-breaking drought conditions, emergency water restrictions, and sweltering heat. But wait, meteorologists are warning that El Nino is on the way, and we might feel its impact as early as mid-summer! Such tough times call for tough plants and a creative new plant palette.

Fear not! Developing gardens around heat- and drought-tolerant plants will not result in desert landscapes of gravel and stone punctuated with the odd yucca or prickly pear. Some of the toughest plants readily available are among the most spectacular in form, color, and fragrance.

If you were contemplating an herb garden to augment your culinary endeavors, you are well on your way to horticultural hardiness. A large number of the most commonly planted perennial herbs actually have pedigrees reaching back to the sun-baked Mediterranean coast. The toughest include the many varieties of oregano and thyme, rosemary, marjoram, mint, sage and bay. In fact, you will need to pay attention to the cold tolerance of some of these heat lovers, especially bay and many of the thymes and sages. Frugal gardeners often prefer to plant the cold sensitive species in pots which they can bring indoors for winter.

Keep in mind that your herbs need not be confined to an herb garden. There are dozens of varieties of thyme which function as superior ground covers in sunny areas, such as borders along driveways and sidewalks, and on steep slopes. These aromatic creepers often feature gold and silver variegated foliage and discretely colorful floral displays. Add to this list of culinary ground covers both prostrate rosemary (Rosmarinus officinalis 'Prostratus') and the brilliant green and white-variegated oregano cultivar called ‘White anniversary.’

Another excellent key when shopping for plants for your drought-proof garden, either alone or as accent features, is foliage texture and color. Generally speaking, plants with fuzzy leaves, such as the aptly-named lambs ears (Stachys byzantina), tend to enjoy the intense heat and dry conditions which would leave their thin-skinned neighbors wilting. Another soft-haired candidate includes the herb betony (Stachys officinalis), which like its botanical cousin, lambs ears, is available in varieties providing leaf coloration from pure silver and white to greenish-gray, and 12-24 inch summertime flower spikes in dusky pink, lavender and magenta. Some of the scented geraniums, called pelargoniums, also offer velvety smooth leaves with wonderful scents from lime and rose to pine and orange.

Similarly, foliage which is noticeably silver, gray, or white, as seen in the species mentioned above, further tends to reflect intense sunlight, helping plants survive even the most infernal days of summer.

Gray santolina, sometimes called lavender cotton owing to its soft, fragrant foliage, is one of the more popular low-growing evergreen shrubs used in either informal gardens, where the bulbous yellow flowers add a splash of color above the gray foliage , or in formal garden settings, where the plants can be clipped to shape.

Dusty miller is a common name often used for an attractive gray-green annual, with wooly leaves and, unfortunately, a forgettable yellow flower spike. Cut leaves are often used in flower arrangements. It is also the name sometimes applied to Artemisia stellerana or beach wormwood, which is often spotted growing along coastal areas and on sand dunes. The most ornate cultivar of this species is ‘Silver Brocade’, whose felt-like, deeply lobed leaves, give it an aristocratic air.

In fact, the genus Artemisia contains a host of aromatic herbs, the wormwoods, many of which are ideal as drought-tolerant ground covers and low shrubs. Artemisia absinthium is the species which provided the infamous alcoholic beverage absinthe and the flavoring for vermouth. However, even non-distillers will enjoy growing other silver-leaved artemisias, including the ever-popular ‘Silver King’ and ‘Silver Mound’.

Beyond a doubt, however, there is no better source for tough plants than our native landscape. Always remember that native plants were thriving in this area long before human settlement and in-ground irrigation. These species have survived blizzards, floods, and droughts, and are perfectly adapted to whatever climatic conditions are served their way.

Tough native plants and landscapes can, of course, be easy on the eye if they are planned properly. For example, select plants with similar heights and different colors and inter-plant them to create a kaleidoscope effect. In an island bed, mix together tickseed sunflower and threadleaf coreopsis with early coneflower, fire pink, and the ever-sturdy black-eyed susan to suggest a vest pocket wildflower meadow. Also consider planting elegant upright grasses like little bluestem, switchgrass, and broomsedge, either grouped together for a native grass garden, or add splashes of color with sundrops, some of the native Liatris species, and Coreopsis and Rudbeckia species.

Natives can provide both resilient and brilliant ground covers with moss phlox, boasting a dense carpet of floral displays ranging from pure white and pale pink, to red, blue, and purple. They can also offer colorful camouflage or a focal points for a fence or trellis with coral honeysuckle, trumpet creeper, and virgin’s bower.

Native plants are also the food and nectar source for delicate native wildlife such as jewel-like hummingbirds and butterflies. Add their living color to your garden by planting joe-pye weed, gayfeather, Monarda species like wild bergamot and horsemint, and the numerous goldenrod species native to our area.

While it may be warming up, gardeners need to keep a cool head and select plants which can take the heat and drought and the forewarned weather wackiness of El Nino in the months to come.

Copyright 2007, Joseph M. Keyser