why have some of my onions and leeks made multiple plants

are they from last year? if yes then that is often what they do. They will fatten up to eat later but remove any flower buds as they form. i have leeks from last year that i will be eating with sunday lunch tomorrow.

It often happens with onion sets. My best results are from seeds sown in March, our show onions were sown in October. Did you plant more than one leek in each hole when you planted them out?.