Paired with a nitrogen fixer, oats can be a cornerstone for your winter cover and soil-building. If you're curious about using oats as a winter cover in Tucson, keep reading...

Why Use Oats as a Winter Cover

Oats are prolific during the Tucson cool season, adding a tremendous amount of organic matter to the soil when chopped and dropped in place. They grow fast and thick, and can easily smother out most other weeds when planted densely.

Oats are a great way to get lots of carbon into your soil fast. They also provide multiple cuttings to be used as mulch, especially when they are cut high.

oats growing as cover crop in tucson early march
Two plots of oats and hairy vetch in March. These covers grew through the late-winter and were chopped before spring planting.

Do Oats Summerkill in Tucson?

Sort of, but not really. I hoped that a cool season crop like this would readily drop dead at the sight of an Arizona summer, but alas it's not so simple.

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In my experience, oats tend to slow down as the late spring heat comes on in Tucson.

They'll keep growing well into the 90's F (30's C), however by June when it starts hitting 100F (37.7C) they'll start to die back somewhat.

I haven't left them growing beyond the arrival of the 100F days, but I assumed by late-june all the oats would fully die back and the summer-kill would eventually be successful.

Unfortunately this is likely far later in the season than you would want, so I don't recommend waiting for summer's heat to kill your oats. You might be waiting a long time before you can plant your next veggie cycle.

oats chopped and mulched but growing back
Oats seen chopped and dropped in late-May in Tucson. Notice small clumps and sprouts of oats popping back up even as temperatures approach 100F. Oats are hearty!

This stubble can still easily be pulled back and planted into.

I've had occasion to plant into oats before June in order to get a spring crop in the ground, so cutting back the oats is an easy option for this. They will likely grow back after a spring cut, though not nearly as thick as before.

I've also chopped and dropped oats numerous times throughout the spring to keep my plots mulched and my roly polys well-fed.

Can You Mow Oats?

Oats are a great option for mowing. You can use a lawn mower, a weed wacker, or a scythe to mow the oats down low. Cutting low helps to terminate oats faster, though they may still grow back after the first mowing.





Stick with it, as subsequent mows will drain the grass of its energy and eventually you'll succeed at mowing down your oat cover.

If you're in a small garden and want to continue to grow & chop oats for continuous mulch, a pair of electric hand shears can be a great tool for cutting around veggies and cash crops.

I did have trouble with this method because of the thick stems, however, and would have preferred to chop earlier and completely with a scythe or weed wacker. This would have been better than having to continue to cut back my oats from around my vegetables.