Black Velvet Rose Geranium seeds should be started indoors in early spring. Once the weather warms up in late spring to early summer, and night time temperatures are steadily above 10°C (50°F), the curious little seedlings can be transplanted outdoors. Continue reading below for more tips on how to grow geraniums from seed.
Pelargonium x hortotum
Exposure: Full sun
Start seeds indoors about 6-8 weeks before transplanting out.
Sow seeds 5mm (1/4”) deep, using sterile seed starting mix. Use bottom heat until germination, and continue unless the room is particularly warm. Pot seedlings on into 4” peat or coir pots about 3 weeks after sprouting.
Harden off seedlings gradually over 1 week, once night time temperatures are consistently above 10°C (50°F). Geraniums are fairly hungry feeders that benefit from rich garden soil and regular feeding with liquid fertilizer or compost tea. Grow in full sun to achieve the best foliar colour.