Onion seeds are short lived and for best results, fresh seed should be used each year.
Regeneration from fresh seed is slow, taking up to a year.
Fresh seeds should be sown, as they quickly dry out.
Fresh seed germinates in 3 to 20 days and requires no special care.
Regeneration from fresh seed is slow, starting after around four months.
Germination from fresh seed is slow, taking six to ten months.
Fresh seed will usually germinate, but should first be dried out a bit.
For so small an area as a window box, buying a packet of fresh seed each year is the most practical.
Approximately 50 to 75 percent of fresh seed will germinate.
In the case of parsnips it is essential to buy fresh seed each year.