Common Names: Candytuft, Evergreen candytuft.
Iberis sempervirens is a well-loved perennial, whose deep green foliage and pure white flowers create form and color at the front of the border and lining pathways. It is a subshruba low growing woody plant spreading to about 2 feet and about 10 inches tall. Iberis sempervirens is one of the best low growing perennials to bloom in the spring with the later blooming varieties of tulips and daffodils.
The ‘sempervirens’ part of the name means “always green” and for most seasons it is reliably green (except in the coldest parts of winter in the Zone 5 garden). It is during the trials of drought, however, when this tough green plant shows its mettle. Despite the beautiful white scallops of flowers in spring, it is this consistently good looking foliage which should win Iberis sempervirens a place in your garden.
The perennial Candytuft, for Candytuft is its common name, blooms from April through June. There is good reason it has received the RHS Award of Garden Merit.
Iberis Sempervirens Description
The perennial candytuft is a mounding subshrub, reaching 10 to 12 inches in height and spreading to twice that measure in width.
The stems have whorls of deep green leaves that are narrow and lance shaped, almost succulent looking.
The spring blooms are what one veritable garden writer called “opaque white”, and they are a powerful visual presence in the garden.
Iberis Sempervirens Growing Conditions
Iberis sempervirens is native to Southern Europe and the Western parts of Asia, Mediterranean climates.
- Sunlight exposure: Full sun to part shade
- Preferred Soil: Somewhat alkaline,pH 6.0 to 7.5; Well-drained, average fertility.
- Hardiness: Zones 3-9
Increasing your stock of Iberis is very easy. The two simplest ways to increase desirable varieties is through division or cuttings. I prefer to take cuttings unless the plant needs to be lifted. Just like Lavender, take healthy sideshoot cuttings no more than 3″ from the plant. Strip off the lower leaves and firm the cutting into your soil. This is best done in early spring or late season when there are reliable rains (or where you will keep the soil moist enough for the cutting to “take”).
Another easy way to increase a plant that grows from cuttings is layering. Iberis sempervirens will root from where a stem makes good contact with the ground, roughing up the underside and then weighting the area to be rooted with a rock or brick will encourage roots after which that portion of the plant can be separated from the parent plant and transplanted elsewhere.
Seeds germinate in about two weeks, plant them in growing medium, sowing indoors March to May. Cover the seeds with a very light “dusting” of growing medium. When watering lightly spray the surface with a fine mist, preferably watering from underneath, as well.
Outdoors: Sow the seeds thinly and lightly cover them with soil when danger of frost is past. Plants usually grow the first year and bloom the next, as with most perennials.
You see how soon an edging of Candytuft can be obtained for the border or to trim a path.
Iberis Sempervirens Care
This plant is easy care and truly a long lived perennial. Its good looks throughout the year mean that the short bloom period is just one reason of many to plant it. Even when plants are low maintenance like this one, a gardener should still give it some attention once in awhile: feeding and grooming keeps the Candytuft growing well and looking its best.
Fertilize through the growing season with all purpose fertilizer, tapering off mid to late summer. A slow release fertilizer at the beginning of the spring is the lazy gardener’s solution. These plants will grow fine without too much attention to feeding, however.
After the candytuft flowers in the spring, it is ready for a light pruning which will refresh the look of the green foliage for summer. One of the wonderful things about this plant is its ability to keep its good looks even in the heat of summer. Recently as we suffered a drought, the Candytuft retained its excellent looks…even when other plants with reputations for great drought tolerance looked rather ragged.
How to Use Candytuft in the Garden
As wall plants or rock garden inhabitants, this plant is right at home. Besides its graceful ways and good looks in such situations, this will provide the good drainage that the Candytuft likes.
Anyplace a low growing plant is needed is a good location for I. sempervirens. Around the base of a mailbox, lining a walk, at the front of the border, as a groundcover for spring bulbs- especially the lily-flowered tulips. It is used in flower boxes and would be pretty in a spring perennial container planting.
Creeping phlox (Phlox subulata), rock cress (Arabis) pasque flower (Pulsatilla), and other low growing perennials. Spring bulbs that bloom during late April- early June, including alliums.
Perennial Iberis Named Varieties
This selection is compact in growth with a dense cover of flowers.
‘Snowflake’ yields abundant, generously sized flowers for a long period of bloom.
Tahoe is a more compact selection -blooms 2 weeks earlier than other I. sempervirens varieties.
Older variety that grows taller than the other selections. Tends to rebloom.
‘Autumn Beauty’,’Autumn Snow’
Lesser known selections, that have a later season rebloom as you might guess from the names.