Mulching Onions

I'm thinking that to mulch onions would be bad news for the onions.  Am I right?  How do you guys keep the weeds down?

Never heard that it is bad to mulch onions, just got finished mulching mine.

if you want to keep weeds down, better mulch them or weed them...

or just use roundup!

we mulch our onions as well. mostly with year old leaf mold piles.

What would lead you to believe that mulch would be harmful to onions?

I have a about 400 onions in the ground right now, will be ready in about a month.  Had I not mulched with 2-4" of leaves, the things would be inundated with weeds.  I could mulch once or pull weeds continually for months.  Mulch saves a lot of work and backaches.

Mulch does more than block weeds.  By covering the soil, the impact of rain on the soil is reduced.  After all the work done to loosen the soil, it would be a shame to let it pack together after just a few storms.  Any weeds that do make it through the mulch are easy to pull from the loose soil.  Mulch is an insulating layer, warming the soil during the cold season, giving the plants a boost and cooling the soil during the warm season, reducing evaporation.  By shading the soil the microbes are better able to flourish, protected from UV rays.

Thank you for puttng my mind at rest.  Someone told me that onions needed to be kept dry and baking in the sun or the necks would rot.  That seemed to rule out a mulch much to my annoyance.  I was going to use old grass cuttings.  Would they be OK?  We don't have much else yet.

when the tops fall over, just pull the onions and put them somewhere dry and hot to cure.

Once the bulbs have formed and the tops have fallen over it is time for the things to cure.  If left in the ground after the tops have fallen, there would be some rot, particularly if they have already formed seed balls.  For curing the onions, pull them out of the ground and leave them on top of the ground or on top of the mulch or move to a shaded spot.  The curing time wants to be dry, so the fellow is kinda right.

All sorts of things are suitable for mulch.  Grass clippings are fine, old or new.  The fresher the clippings, the more likely they are to matt together.  This is not a problem as a mulch, its the same as hay.

I use a straw mulch on mine usually and it doesn't give me any problems.

If the grass matts together, can the water still get through?

Water will get through just fine.  The grass will dry in just a few days.  Once dried it will also absorb rainwater, but most of the water will filter through.

I'm feeling glum about the grass cuttings mulch.  No I haven't yet mulched the onions but was encouraged to do so until...

I planted potatoes and mulched the rows with grass cuttings giving me the added bonus of seeing where the rows were in this massive field we've had turned over.  The last few rows didn't get a mulch as some other kind person helped me finish the job.  Now every single unmulched potato is through but the mulched ones are VERY patchy and that makes me grumpy cos now he (my 'helper' other half) thinks I don't know what I'm talking about - grrrr.

When I transplant, the plant is several inches high.  Mulch covers the soil but not the plant.
When I sow directly, I wait for the plants to reach a few inches in height before mulching or the seedlings will be shaded, resulting in the loss of some plants.  I'm thinking I should have said something.

Potatoes have lots of stored energy.  If you gently rake or move aside the mulch where a plant has not appeared, the shoots will be exposed to sun and will probably be just fine. 

With some plants mulched and some not mulched you have a perfect setup to observe the difference between the two methods.  I would project lots of weeding where the plants are not mulched, even if all plants are hilled in a similar fashion.