Welcome to GOY. Onion plants grow from onion seed or sets. Sets are small onions. Both seed and sets can be found in any garden centre and also in your local supermarket. The link below shows you how to grow onions. If it is ornamental onions for the flower border you mean they can be bought now in the same places. They will be bulbs which get planted in Autumn and flower in Spring or early summer. Good luck. http://www.bbc.co.uk/gardening/basics/techniques/growfruitandveg_growingonions1.shtml

Onions are grown from the seed of Allium cepa, {onion} Derek.

I suspect this is our 'friend' mate from this morning. I will wait and see how other responses show up.

I bought my onion sets 3 weeks ago, put 50 in and have 47 coming up already. Disappointed about the other 3 though !

Yes I think so too Sbg, Derek.

Ah Hank... we have to wait until spring to plant onion sets! To cold and damp in the winter. Going to stop following this post as I agree Roses is just a different name for Meanie.

Seeds or sets grow into rush-like plants with the distinctive onion odor. They are often harvested at this stage as green onions, or scallions. Allowed to grow, most varieties develop bulbs underground, in spring for short-day varieties--which are more commonly grown in mild-winter climates, such as mine--or in summer, for long-day varieties. These bulbs are the onions that you buy in the store.