Evergreen Candytuft

Family: Brassicaceae, alternatively known as Cruciferae (Mustard family)
Genus: Iberis
Species: sempervirens

When events in the larger world turn worrisome, I tend to seek out the friendly and familiar for refuge and comfort. Meatloaf and mashed potatoes appear again on the family menu—much to my son’s delight—followed by nothing more fancy than brownies or chocolate-chip cookies for dessert. I’ll choose a book by Edna Ferber over a brilliant but edgy new novel. And in the garden, I find my attention returning to the most dependable, tried-and-true performers, the plants that keep showing up, year after year, to do their best in the sometimes obscure corners where I’ve left them, unattended, as I’ve waxed enthusiastic over some flashy new Superstar of the plant world.

If meatloaf is a comfort food, then evergreen candytuft—Iberis sempervirens—is a comfort plant. This woody-stemmed, herbaceous perennial that tops out at 18 inches shares its species name—sempervirens, meaning “always green”—with the tallest living species on the planet. The coast redwoods of California—Sequoia sempervirens—can easily reach 350 feet. Evergreen candytuft is very short and coast redwoods are very tall—but I suppose it could be said that what I. sempervirens lacks in stature, it makes up for in…lovely white flowers. Each with four petals, they’re gathered in flat-topped bunches called “corymbs” that cover the entire plant in full bloom.

Iberis sempervirens is native to southwestern Europe—hence the name of the genus—and in our area is hardy and evergreen, although it does look a little straggly during the winter. There is enough leaf surface for it to be susceptible to desiccation and to sunscald in the winter months—not too much of a problem here in Whatcom County, since we don’t have many dry sunny days from November to March. If a clear northeaster is forecast, you can take the precaution of covering your candytuft with evergreen boughs, which are readily available in most of our yards after one of those windstorms that blow through every week or so. Candytuft also appreciates a mulching to lessen the effects of the freeze-thaw cycle on its leaves and its relatively shallow root system.

In late winter, candytuft will bounce right back from any cold-weather nipping. By mid March, it begins producing flowers of the purest white imaginable. They will freshen up any border, no matter the color scheme of your spring bulbs, with white flowers sparkling against finely textured, deep-green, lance-shaped leaves. The species is very attractive, and several worthy cultivars are widely available, including ‘Alexander’s White’, an early bloomer; the dwarf ‘Little Gem’ and ‘Snowflake’; ‘October Glory’, another small variety that repeats its bloom in the fall; and ‘Summer Snow’, a late bloomer with particularly large flowers.

Place candytuft in full sun as an edging, or let it spill over a rock wall. You can expect your I. sempervirens to spread about as wide as it is tall. Make sure the soil is well drained and rich with organic material, and if it tends to acid, add some lime. In poorly drained, acidic soils, candytuft is susceptible to both crown rot and club root. Known in Europe since the 1200s, club root is caused by a fungus that plagues all members of the mustard family, vegetables as well as ornamentals. It is a significant problem for commercial growers but much less bothersome to home gardeners. If your candytuft falls victim to it, however—you can get a firm identification at the Master Gardener office, but signs include misshapen branches, withered, yellow leaves and deposits of mysterious slime—you’ll want to avoid planting any other cruciferous plant in the same area.

Evergreen candytuft is quite easy to care for, so long as you give it good drainage. The one chore required is shearing it after bloom. Forming seedpods weakens the plant, so cut the faded flowers right off at the foliage line. You’ll find yourself removing up to one-third of the entire plant, but it will fill out again very quickly to a lovely green mound as it begins to set next year’s blooms. Its stems are quite brittle and easily broken, so take care when raking around candytuft, particularly during fall clean-up. If stems do snap off, they will root quickly if you give them a dip in rooting hormone and pot them up immediately.

Candytuft looks very nice planted in drifts over bulb beds. You can shear it at about the same time the bulb foliage has dried up enough to be removed. If you discover other perfect places for it and you need more candytuft, you can use stem cuttings or grow it from seed. In my garden, I find just the right number of volunteers. Candytuft is a relatively short-lived perennial, so I replace old plants every five or six years.

Deer, rabbits, and slugs all avoid candytuft. I suppose it has the pungent qualities of many members of the mustard family. Don’t be making a sauce out of it for your meatloaf, though. Meatloaf doesn’t qualify as comfort food unless you serve it with lots of old-fashioned, bottled ketchup. Nothing but the red stuff will do.