Dimorphotheca pluvialis (L) Moench
Common names: rain daisy, Cape daisy, white Namaqualand Daisy, ox-eye daisy (Eng.); witbotterblom, witmargriet (Afr.)
Dimorphotheca pluvialis is always one of the first spring annuals to flower at Kirstenbosch.
Flowering in masses the glistening white daisies look like snow covering the ground of the large annual beds, small pockets along the footpaths and rockeries. For the best display it is important to visit the garden on a sunny day as these sun loving daisies only open with the warmth of the sun from about 10 o'clock in morning to 4 o'clock in the afternoon. As the sun moves across the sky their flowers follow, always facing the sun.
Dimorphotheca pluvialis forms a bushy plant that is covered with large white daisies all flowering at the same level. The flowering season is from July to October, depending on the rain. The narrow leaves are light green, about 7 cm long and have indented edges. They are numerous at the base of the stems, becoming fewer and smaller near the top.
Distribution and habitat
Dimorphotheca pluvialis is an annual endemic to Namibia, Namaqualand and the south western Cape. During spring huge fields are covered with this bright white daisy, forming a dazzling mass.
In their natural habitat the flowers are pollinated by small horseflies that get covered with pollen as they fly from one daisy to the next in search of tiny amounts of nectar.
These annuals are adapted to germinate, grow, flower and set seed during the rainy winter and to survive the long dry summer as seed. The seeds are interesting in that two different forms are produced. The ones we usually sow are flat, papery and fly away easily in the wind. They are formed in the center of the flower by the disk florets. The outer ray florets form seeds which looks like little thorns with a thick coats. Under favorable conditions the papery seed of the disk florets germinate in abundance, while the seeds of the ray florets have delayed germination to protect the species against unpredictable conditions in their arid environment.
Kirstenbosch grows two different forms of Dimorphothece pluvialis, which were selected from plants growing in the wild. Dimorphotheca pluvialis 'Flat White' (below) has pure white flowers, with its petals backed with mauve, and a yellow centre. The plant grows about 15 cm high.
Dimorphotheca pluvialis 'Purple Centre' (below) also has white flowers but with a deep violet ring around the yellow centre. It grows to about 40 cm in height.
Growing Dimorphotheca pluvialis
This species grows easily form seed. The best time to sow is in autumn directly into the planting beds or first in seed trays or seedbeds from where the seedlings can be planted out. Scatter the seed on well-prepared soil with good drainage and in full sun. The seeds can be lightly covered with sand or fine milled bark. Germination is fast, usually within 4 days. Watering the young seedlings regularly is important, as the young plants require plenty.of water. The annuals respond very well to fertilizers but only apply fertilizers if the plants look stunted or deficient otherwise they grow to soft. The annuals transplant well and within 3 -4 weeks after germination they usually a good size to handle. When planting be generous with the annuals, as a very full and rich effect is gained by close planting.
Many beautiful and interesting displays can be made by mixing the different annuals like the blue flax (Heliophila coronopifolia) which grows tall and thin, Felicia heterophylla a striking blue daisy and the brightly coloured Bokbaai vygies, Dorotheanthus bellidiformis. Bulbs like the arum lilies (Zantedeschia aethiopica) and watsonias grown in clumps work very well mixed with the annuals. At Kirstenbosch we collect all our own seed from the garden to be sown again the next year. If the seed is not collected Dimorphotheca pluvialis usually seeds it self the next year. Dimorphothecea pluvialis has no major pests at Kirstenbosch other than the guineafowl, which love to eat the soft new growth.
Liesl van der Walt
Plant Type: Bi/Annual
SA Distribution: Northern Cape, Western Cape
Soil type: Sandy, Loam
Flowering season: Spring, Winter
PH: Acid, Neutral
Flower colour: White
Aspect: Full Sun
Gardening skill: Easy