Winter purslane

Winter purslane is a winter annual: you sow it from August/September, it grows as a rosette through the winter and survives frost down to about -15 °C outdoors without protection; there is nothing to dig up or bring indoors. In spring, let a few plants go to seed, and it often comes back by itself the following autumn.

You propagate winter purslane (Claytonia perfoliata) only from seed. Vegetative methods are not practical for this annual species, as it forms no rhizomes, runners, bulbils or woody shoots. Sow directly outdoors, best between mid-August and the end of September. Important: winter purslane only germinates in cool conditions. The seed only comes up once the soil temperature falls below about 12 °C (8 to 12 °C is ideal). If it is still too warm when you sow, the seeds won't germinate. Because winter purslane needs light to germinate, only press the seeds in lightly or cover them with at most 0.5 cm of soil. Mix the very fine seed with a little sand before sowing so that it spreads evenly, and keep the substrate evenly moist, but not wet, until germination (about 7 to 14 days). A row spacing of around 10 cm is enough, as the rosettes stay compact. The special thing: once winter purslane has established in the garden, it reliably self-seeds after flowering and returns year after year without any effort from you. After the first time, you hardly need to sow actively any more. Keep an eye on where it grows, as it spreads strongly in places. Unwanted seedlings are easy to pull out because they root only shallowly. If you want to limit self-seeding, harvest the shoots together with the flowers before the seeds ripen.