Some advice is to water amply in spring and then sparingly in summer - to avoid fungal problems that can occur with alliums. In the past we've had the occasional year where fungus has ruined most of the garlic, but never had this sort of issue with onions.

By the way, onions are Copra and Walla-Walla (former as a keeper, latter as a summer globe onion), and Redwing as a decent keeper red. All are planted in slightly raised beds, with Walla Walla seedlings 5" apart in rows 5" apart, the other varieties are 4" apart in rows 4" apart.

I notice that "industrial" onion fields - conventional chemical farms - often seem to be irrigated fairly heavily. The advice to water sparingly seems, perhaps, more often to be found on internet sites aimed at home gardeners. I'm not sure when/if the conventional farmers may cut back on irrigation.

Other people's comments and advice are also welcome.

Same for feeding. A one time when planting isn't sufficient and neither is only compost as a source of nutrients. Nutrients are used up through the season, N vaporizes, the soil food web that makes compost effective ages and dies without regular refreshing and supplements, etc. And there are numerous nitrogen organic supplements available to use throughout the season.

I notice that "industrial" onion fields - conventional chemical farms - often seem to be irrigated fairly heavily. The advice to water sparingly seems, perhaps, more often to be found on internet sites aimed at home gardeners. I'm not sure when/if the conventional farmers may cut back on irrigation.

Personally I have never heard or read that growing in a home garden is any different than growing them commercially. Nor does "industrial" onion fields (meaning commercial growers) equate to "conventional chemical farms". There are many OMRI Certified commercial onion growers.

Dave

A side not on your side note: Apologies that the details of what I wrote seemed inaccurate to you. Of course, not all "commercial farms" are run by "industrial farmers" - and not all commercial onion growers are "chemical" (rather than "organic"). In the region where I live, most organic commercial operations are largish garden or fairly small field croppers. But my reference simply meant that really large onion fields, in my general region, are generally non-organic. Further, that these operations (from what I've been able to learn) tend to gather their cultivation info from sources different from those drawn on by organic homesteader/gardeners, such as myself.

Here are a few pics of our onions - they aren't what you would call huge onions - but I like to let the onions speak for themselves. We have to pull the onions from our garden before freezing temps destroy them in the fall in our zone - even before the are ready to be pulled - then cure them in the GH for storage. We are still eating onions that were cured last fall - they have stored very well!

The drying skins at the top can accumulate rain, whick, if not quickly dried, can start to rot. This can not only ruin that cover layer to the onion but can tranfer some of the fungus to healthy, growing leaves.
-Terry