Allium sphaerocephalon

Germination

Sow directly where they are to flower at any time of year, or sow indoors, then overwinter seedlings in the greenhouse and plant out the following spring. To sow directly plant seeds 20mm deep, winter cold will naturally stratify the seeds with seedlings emerging the following spring. To sow indoors surface sow onto moist well-drained seed compost, just cover with soil. Ideal temp. 18-22°C for 2-4 weeks. Then cold stratify -4°C-+4°C for 4-6 weeks then return to warmth 5-12°C where the seeds should germinate. Germination can be slow and erratic taking 18 days-12 months. Repeat warm/ cold cycle if germination does not occur. Transplant seedlings when large enough to handle to 8cm pots and grow on. Acclimatise for 10-15 days before planting out.

Growing

Alliums thrive in sheltered, sunny, open, well-drained sites. They do not like cold, exposed or waterlogged conditions. Avoid planting in freshly manured soils. If your soil is heavy/ clay add grit to improve drainage.

Cultivation

The leaves, which can be straggly, begin to die down at flowering. For this reason Alliums are best planted where their foliage can be masked by other plants. Pruning is not required. Lift and divide overcrowded clumps after the foliage and flowers have died down. This variety produces aerial bulbils in the flower head. Carefully remove and separate bulbils and plant them in moist, well drained compost with 25mm spacing, cover with 10mm soil.