Plant Taxonomy of Purple Ice Plant:
Plant Type for Delosperma Cooperi:
Characteristics of Delosperma Cooperi:
The book, Hardy Succulents, by Gwen Moore Kelaidis, was useful in my research into hardy ice plants. Purple ice plants, as their name suggests, have light purple flowers, which are daisy-like. The flowers bloom all summer.
Kelaidis remarks that Delosperma cooperi can spread to as much as 3-4 feet across. Delosperma cooperi stays relatively short (about 3 inches tall) and is procumbent in habit. The rounded, fleshy fingers of the foliage are about an inch long; the green summer color of the leaves may morph into darker colors as temperatures drop.
Planting Zones for Purple Ice Plant:
This succulent is indigenous to South Africa, where it is an evergreen. Belying its origin, a hardy ice plant can be grown in planting zones 5-9. At the northern end of this range, however, note 2 things:
- Winter hardiness isn't a given. Purple ice plant may not survive a difficult winter in zone 5.
- Its leaves won't be evergreen, even if it does survive; treat it as an herbaceous perennial.
Sun and Soil Requirements for Delosperma Cooperi:
Planting Delosperma cooperi in full sun and in a superbly well-drained soil are critical steps to growing this succulents successfully. Avoid planting in clayey soils unless you are willing to improve percolation with soil amendments. Purple ice plants are drought-resistant plants and don't require rich soils, but they hate to be sitting in water!
Despite its resistance to drought and dislike of wet feet, Delosperma cooperi will profit from an occasional watering in the heat of summer, as long as the drainage is excellent.
Uses for Purple Ice Plant:
Care for Delosperma Cooperi:
It isn't so much cold weather in zone 5 that will kill Delosperma cooperi as it is freezing temperatures combined with wet conditions. Thus a Delosperma cooperi is more likely to survive in a zone 5 region with an arid climate. Kelaidis recommends "a winter blanket of woven row cover (like Reemay)" to help over-winter it in wetter zone 5 climates.
Reduce watering in fall to help harden off Delosperma cooperi for winter. Cold will be less likely to damage their succulent leaves if they aren't quite so full of water.
As a side note, the water-retentive quality of this succulent's foliage makes it a fire retardant!
Origin of the Common Name:
Kelaidis mentions a number of other varieties besides Delosperma cooperi; for example"
- Delosperma basuticum 'White Nugget' has white flowers
- Delosperma 'Gold Nugget' bears yellow flowers
- Delosperma 'Kelaidis' has the most unusual flower color, a salmon-pink
In addition to flower color, such features as size and growing requirements distinguish one variety from another. For example, Kelaidis calls 'White Nugget' "more of a clump-former than a ground cover" (i.e., it doesn't spread vigorously enough to be considered as effective a ground cover as Delosperma cooperi). She also indicates that Delosperma nubigenum, a variety with yellow flowers, tolerates clayey soils better than does purple ice plant.