can i grow allium from seeds off my plant

double entry

I may have answered this on here before, but will do it again.
Sow the seed when it begins to fall from the seed head (little black things). Sow thinly in ordinary compost in a deep pot and cover with grit. Leave the pot somewhere safe, but exposed to the cold over winter. They germinate in Spring. Do not prick out. Leave in the pot and feed with dilut feed every 2 weeks until the leaves die down like the parent plant does. Allow to dry off and leave somewhere safe and cool. They should be kept on the moist side of dry, but not sodden.
The following spring when they begin to gorw again repot the whole pot in a deeper pot and repeat the feeding. They can be separated and grown on after that. They take from 3 to 5 years to reach flowering size.

Owdboggy, when you say 'ordinary' compost do you mean, say, multipurpose or would seed and cuttings compost be better?...thanks..

Either would do, Add some sharp sand though to improve drainage. By the time the seeds germinate any nutrients in the compost would have washed out anyway.