This post was originally published in 2006. Since then I keep getting googled on the subject and comments still appear from time to time. Here it is again:
1. Try to keep the leaf tops as long as possible do not trim them. When drying them it is best to string when they are slightly moist otherwise they will snap if they are bone dry.
2. Choose any onion with the longest, strongest leaf; this will be your primary vertical stalk. Take another onion and hold it next to the first, then take the second stalk round the back of the vertical then towards you, then under the neck of the 2nd onion , then take both stalks vertical. So the 2nd onion stalk has gone 360 degrees round the vertical stalk, under itself then up.
3. You should now have two vertical stalks, hold them together just above the join.
4. Take a 3rd onion, place it next to the 2nd and take the 3rd stalk 360 degrees right round the two vertical stalks, under itself and then up. You should now have 3 vertical stalks which you hold tightly just above the join.
5. Continue like this, fitting in the new onions as close as possible. The vertical stalks will replace each other and you can make the string as long as you want, shorter ones about 12" are best and strongest. Personally I find 12" is just fine for me.....
6. It is important to keep hold of the vertical stalk just above the top onion at all times. When you have created your desired length.... tie a string round the top making a loop to hang it. Alternatively, start by tying string round the very bottom stalks and wind string round the central stalk all the way up for extra stability and then tie a knot and a loop at the top.
7. Trim the straggly bits at the top, stand back and enjoy your creation - hang them on your bicycle bars and ride round town!