Cutting time for Oat Covercrop to avoid reseeding.

Hello,
I've been a lurker here for quite awhile and decided to sign up. I own a smaller garlic and hot pepper startup farm and hopefully will begin selling this year to the permies. Last year I produced a few thousand lbs of peppers and a few hundred lbs of garlic and donated all of it. This year is scaled up even further and I plan to have 1/2 acre of garlic densely planted this fall.  I've purchased a 5 row garlic planter from europe, I plan to develop some sort of notill/lowtill weed free method of planting garlic every year. Right now the plan is to plant 1/2 acre of Oats, i'll run the planter through the tall oats planting the garlic than i'll chop and drop the oats with a sicklebar mower (just a sythe for this year, ill probably buy the mower next year if I like this method). I'll than rake the long oats on top of the garlic beds as best as I can. Eventually I will have a compost spreader that I can drop a layer of 1"-3" thick well composted leaf and manure compost on top of this as nutrients and further weed supression.

My question is, when does the oats become viable seed? I will need to chop the oats before this happens so i dont get a large crop of oats comming up as well.

Thanks for the input

The website Sustainable Market Farming has many articles on cover crops Here is a recent one.

The choice will depend on your location. Of the several cereal cover crops, oat is less cold hardy and will be winter killed in zone 7. The timing for planting and terminating are important too. Related topics are all covered in details in those articles.

I have always tried to cut my weeds before they developed a seedhead.

Do you want to leave the oats long enough to harvest the oats?

I think you would be set to cut if the oats reached the 'milky' stage. This is when you squeeze the grain and it bursts with a milky substance. You might decide to chop right before this if you want to be double safe which is fine as well.