Agathosma serpyllacea Licht. ex Roem. & Schult.
Common names: thyme buchu (Eng.), wildeboegoe (Afr.)
This pink, white or purple flowered buchu is an eye-catcher in a pot or in the garden when flowering.
Agathosma serpyllacea is a rounded, single-stemmed shrublet between 30 - 80 cm high.
The narrow, needle-like to lance-shaped leaves are swollen behind the tip and slightly twisted. They are 5 - 10 mm long, concave above and hairless or variously hairy.
The tips of the branchlets bear clusters of pink, purple or white flowers with petals 3.5 - 5.5 mm long, and with lance-shaped or peg-like staminodes (sterile stamens). The flowering period is from May to December.
The ovary and fruits are 3-segmented.
Agathosma serpyllacea is not threatened and has a status of Least Concern (LC).
Distribution and habitat
This buchu is found from Clanwilliam to Humansdorp where it grows on limestone slopes and hills or in sandy areas close to the sea and further inland.
Derivation of name and historical aspects
The genus name Agathosma is derived from the Greek word agathos which means good. Osme refers to the distinctive fragrance which is so characteristic of the genus. There are oil glands present on the leaves and fruits that normally release an aromatic fragrance when crushed.
The specific epithet, most authors agree, is derived from Serpyllum the classical Latin name for thyme; serpyllacea therefore means 'like or resembling thyme'. Lichtenstein, who saw the plant in the veld, compared A. serpyllacea, fragrance and all, to a species of Thymus. Kesting 2004 however, suggests that serpyllacea, refers to the slightly twisted leaves and that serpyl is derived from serpula which means small serpent.
There are currently 150 species of Agathosma. Most of these are confined to the Western Cape of South Africa.
As with most buchus, bees can be observed visiting during flowering. It is possible that they do assist with pollination.
No cultural or medicinal uses have been recorded. This buchu is becoming increasingly popular as a landscaping subject. It thrives in sandy soils and unlike most fynbos plants, it does equally well in alkaline and acidic soils. It also thrives as a potplant.
Growing Agathosma serpyllacea
Sow the seed during autumn. Use a medium which is light and drains well. A mixture of equal parts sand and compost, or just plain coarse river sand, will do. Cover seed with a thin layer of bark or sand and than water. Keep the seed tray in a covered area that provides ample good light and ventilation. Ensure that the medium never gets overwatered nor is allowed to dry out.
Germination takes between 4 - 9 weeks.
Prick out the seedling by the time the first four true leaves appear. Ensure that the fine roots are handled with care. Place the potted plants in a shady area for 3 - 4 weeks to harden them off before placing them in the sun. This period is also a good time to pinch out the growing tips of the seedlings as it promotes more bushy growth habit. The young seedlings can now also be fed with some balanced nutrient products. After 8 to 9 months plants will be ready for transplanting into the garden.
This buchu can also be propagated by taking heel, tip or semi-hardwood cuttings. Use fresh material from the current year's growth. Make cuttings of between 25 - 55 mm, remove about a third of the foliage and cut them below the node. Dip cuttings in a rooting hormone and place them in trays with a medium consisting of equal parts of bark and polystyrene.
If available, place cuttings in a mist unit with heated benches. If you have no special equipment, place cuttings in a protective environment such as under waterproof-sheeting. Keep cuttings damp at all times. This could be done by using a fine sprayer or seal the cuttings of in a plastic bag.
It takes 9 - 11 weeks for roots to develop. The rooted cuttings must be hardened-off (prepared for their final outdoor site) for 2 - 3 weeks. Pot the rooted cuttings into a well-drained mix and then move them to a shady area for 2 - 4 weeks to harden off. After this they can be moved into full sun.
Agathosma serpyllacea performs best in full sun and well-drained soil. The ideal time for planting is between autumn and winter during the rainy season. This allows plants the opportunity to establish themselves in the garden before they have to cope with the harsh heat or drought during summer.
Before planting commences, it is advisable to dig over the soil, add compost and a slow-release fertilizer. This will also aid with aeration of the soil.
Some companion plants for this buchu include: Coleonema album, Elegia tectorum, Delosperma litorale, Lampranthus aureus, L. amoenus, Jordaaniella dubia, Leucospermum patersonii, Pelargonium betulinum, P. capitatum, Lobelia valida, Chrysocoma coma-aurea, Crassula dejecta and Geranium incanum.
Space plants at intervals of 20 - 30 cm which should provide enough space to encourage growth. Buchus prefer a relative dense planting as it helps to retain soil moisture. Plants must be watered well during winter. In summer watering should just be moderate, however do not allow plants to dry out completely. Regular mulching will also assist in keeping the soil and roots cool during summer.
- Goldblatt, P. & Manning, J. 2000. Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9. National Botanical Institute, Pretoria & Missouri Botanical Garden, Missouri.
- Goldblatt, P. & Manning, J. 1996. West Coast . South African Wild Flower Guide 7. Botanical Society of South Africa, Cape Town.
- Gould, M. 1992. The buchus: cultivation and propagation. National Botanical Institute, Cape Town.
- Kesting, D. 2004. Botanical names: Derivation and meaning. Wild Flowers of the Cape Peninsula. Flora Documentation Programme, Cape Town.
- Manning, J. 2007. Field guide to Fynbos. Struik, Cape Town.
- Powrie, F. 1998. Grow South African plants . A gardener's companion to indigenous plants. National Botanical Institute, 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 2009. Strelitzia 25. SANBI (South African National Biodiversity Institute), Pretoria.
- Stearn, W. 2002. Stearn's dictionary of plant names for gardeners. Timber Press, Portland, Oregon.
Kirstenbosch National Botanical Garden
Plant Type: Shrub
SA Distribution: Eastern Cape, Western Cape
Soil type: Sandy
Flowering season: Spring, Early Summer, Winter
PH: Acid, Alkaline, Neutral
Flower colour: Purple, White
Aspect: Full Sun
Gardening skill: Easy