A hardy sun- and semishade-loving, attractive, ice pink, perennial vygie ideal for most garden situations.
A fast-growing, sprawling, succulent perennial with a semi-prostrate, mat-forming growth habit. Drosanthemum striatum only lives for about five years under normal garden conditions.
Plants can grow to 25 cm in height. Stems are covered in glistening papillae (hairs), hence their common name ice plant. Leaves are subcylindrical (not quite round), obtuse (blunt or with rounded tip) and 20–25 mm in length. The leaf stalk (petiole) is short, and flower petals are white, silver-pink or deep pink. Each petal is marked with a central stripe. Flowers are 20–30 mm in diameter and appear from late August to late September. Seed is produced in a woody capsule and seed matures in late January.
Drosanthemum striatum is considered Vulnerable (Raimondo et al. 2009). Only ten natural populations remain in the wild. D. striatum populations are declining mainly due to the expansion of wheatlands, vineyards and olive orchards.
Distribution and habitat
Drosanthemum striatum is endemic to the southern part of the Western Cape. It occurs naturally in Malmesbury shale in lowland renosterveld.
This mesemb is relatively hardy, tolerating mild frost (-2°C). Drosanthemum striatum tolerates dry, hot summer temperatures of 40°C and above. It can be grown successfully in most gardens in the Western Cape and in other parts of South Africa, but not in areas of high summer rainfall and in subtropical areas.
Derivation of name and historical aspects
The genus Drosanthemum is derived from the Greek drosos which refers to the glistening bladder cells on the leaves which look like dew drops, and anthos which means flower. The specific epithet striatum is from the Latin, meaning striped and refers to the line which runs down through the middle of the petal.
Drosanthemum is a fairly large genus with nearly 70 species, occurring mainly in the winter rainfall areas of southern Africa. Most Drosanthemum species have showy conspicuous flowers which attract suitable pollinators.
Pollinators are essentially moths and bees. Drosanthemum striatum flowers after 11am in the morning and on into the evening. It is likely that moths pollinate the flowers after 5pm.
Uses and cultural aspects
Horticulturally, Drosanthemum striatum is very versatile and is an attractive feature in most garden situations. Apart from doing well in arid regions where water is scarce, it also does well in Cape Town gardens, even during relatively wet winters.
Drosanthemum striatum is suitable for both full sun and semishade conditions. This is possibly one of the only mesembs that actually flowers well in both semishade and full sun situations. D. striatum grows very rapidly from young seedlings and, if planted in April, will flower by September of the same year.
Growing Drosanthemum striatum
Drosanthemum striatum is cultivated mostly from seed. Copious amounts of seed are produced after flowering, normally around late January. Seeds are light brown and each seed is about the size of a pin head.
Seed should be sown in late autumn (May). Sow the seeds in open, flat seed pans using a well drained loamy soil mixture. Ensure that seeds are not sown too thickly otherwise they may damp off (rot) when they germinate. Firm the seeds down with a piece of flat board and cover the seeds with a layer of sieved river sand.
Keep the seed pans in a well ventilated area where there is good light. Water with a fine spray head. If conditions are warm and windy, it may be necessary to water on a daily basis. Rather water earlier in the day as opposed to the end of the day. The reason for this is that humidity increases as nightfall approaches thus increasing the risk of damping off.
When the seedlings are 50 mm or higher, transplant them either into one pint plastic bags or small plastic containers. Keep them in a semiprotected location at first until they are sufficiently hardened off. They may then be moved outside. It is recommended that they have at least three weeks to harden off completely.
Growing Drosanthemum striatum from cuttings
This is mainly done when selecting particularly striking colours or compact growth forms. The most successful method is to take fresh, supple tip cuttings approximately 70 mm in length.
Treat the material with a rooting hormone prior to striking in a growing medium. Ideal rooting mediums are essentially 50% washed, sieved river sand, 25% perlite and 25% vermiculite. Good drainage is the key to good rooting.
The ideal time to root these cuttings would be in May or June (southern hemisphere). Once roots have formed, normally from the nodes (where buds come from), transplant into light loamy soils, harden off for three weeks and move to an outside location prior to planting.
References and further reading
- Court, D. 1981. Succulent flora of southern Africa. Balkema, Cape Town.
- Raimondo, D., Von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. & Manyama, P.A. (eds). 2009. Red List of South African plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
- Van Jaarsveld, E.J. & De Villiers-Pienaar, U. 2000. Vygies gems of the veld. Grafica Quadro, Tradate (VA), Italy.
Karoo Desert National Botanical Garden