You'll need 13 onions  for this project. This technique will work with cloves of garlic , too. Trim the roots of the onions to about an inch long and gently brush off any soil clinging to the bulbs. Choose the three largest onions for the bottom of the braid. Position one onion at the top and the two other large onions slightly below and to each side of the first bulb.
Next, take the leaves from the leftmost bulb and fold them back over the necks of the center and rightmost bulbs and then wrap them underneath. Pull the leaves tight and then place them back in their original position; this makes a "knot" at the base of the braid.
Then take an onion  and place it on top and in the middle of the first three onions. Line this new onion's leaves up with the leaves of the center onion. You should now have three strands of leaves. Braid the three strands of tops together twice (just as you would hair), making sure that the braid is tight.
Add two more bulbs, one to each side of the braid. Line their leaves up with the two existing outside braid sections; then braid the tops together twice.
Following the directions above, continue to add one onion, then two onions to the braid until you have used all the onions. The top of the braid should finish with a single onion. Braid the remaining tops together, and secure it by wrapping sisal twine around the end and tying it off. Voila!