I did not need to wait 30 days to braid our onions (20 would have been plenty) but they were stored well on an old screen door, in the shade , under a roof until I found time.
These are Patterson "long keeping" onions we grew. They are a "long storage" onion. A "long day" for those of us that live way up north.
I only braided a few bunches of 12 -15 per braid. Lots of the onions will be stored in the basement on newspaper at 55F in the dark until needed.
I did not do a braiding video since there are so many online. If you are interested, search youtube for a video titled How to Hang Onions for Long Term Storage Easy Old Fashioned Way! She does a good job explaining.
The only other tip I would give to trim EVERY root hair, right, tight to the bottom of the bulb for longer storage since moisture uptake from the air can be a issue and try to braid all same size onions in a bunch.
