Ok, great! In that case, break the seed stalks off close to the top of the bulb, keep them well watered until the tops start dying back, then cut back on water. If they've produced decent bulbs but not all are dying and falling over at the same time, you can "walk them down"... just gently press the tops over onto the ground.
They actually do put a bit more size on while the tops are dying down, as well as putting more skin layers on, which helps them store. We're in a very different climate (just planted 900 long day onion plants, just in time for a warm soaking shower to water them in), so I suspect you may be trying to beat the heat, so let them grow as long as you can. But once they have mostly dried down, pull them and spread them in an airy spot... I used to use our deck, but a pallet will work. Let them cure and dry for a few days, then store.
And of course we want pics! Our last snow just melted last week...the only things planted so far here are peas, carrots, spinach, lettuce, snow peas, some herbs and the onions. Will put in potatoes next week. Our last frost date was always Memorial Day... over the past 40 years, it moved up closer to May 10th. Now it seems to be rapidly changing back!
Summerthyme