Broad-leaf Wild Thistle
Berkheya speciosa, Broad-leaf Wild Thistle; Skraaldisseldoring (Afrikaans); ikhakhasi elikhulu (Zulu)
This wild thistle is the most commonly found one in the coastal grasslands of KwaZulu-Natal but try to find this species in any plant nursery selling our native flora and you probably won’t have much luck. This is a pity because this plant does really well in a garden bed or even on a planted roof. I’ve resorted to growing my own plants from seed that I collect each spring, once the seed heads have ripened.
The seeds are carried in the closed spiny bracts at the base of the flowers, which will each produce about 30-50 seeds. The seeds of Berkheyas are shaped like tiny little shuttlecocks that act as rudimentary parachutes or wings to allow the wind to carry the seed away from the parent plants. This dispersal method creates waves of Wild Thistle plants along road verges and in the grasslands.
Sow the seed as soon as you have collected it from the plants. Sow in a shallow seedling tray filled with a seedling mix of 1 part coarse river sand to 1 part sifted leaf litter or compost. The seed will germinate in about 2 weeks from sowing. The trays must be left a warm sunny spot, with a little shade (about 20%) so that the seedlings do not get too scorched by the sun.
After about 3 to 4 weeks, you can prick the seedlings out of their tray into individual small black growing bags of about 100mm diameter. This will let them develop well before you plant them out into the garden in about a further 4 or 5 months. I tend to leave my seedlings in their bags till the following spring. This gives the young plants the best chance of growing during the summer and to set their roots before the next dry winter.