So you want to mulch your garden to keep weeds at bay all winter, but storebought mulch is out of your price range.  What can you do?

Oats used as a cover crop are the cheap and easy way to grow your own winter mulch.  Prices went up 35% since last year, but a 48 pound bag of oat seeds still cost only $16 at our local feed store.  I sow my oat cover crop very heavily since I want to make sure weeds are shaded out, but the oats are still far more economical than a bale of straw.  My 48 pound bag of oat seeds produces the same amount of aboveground biomass as approximately 12 bales of straw ($48), not to mention the nitrogen the roots capture and keep in circulation and the extra organic matter produced underground.

An oat cover crop instead of a heavy winter mulch of straw has another benefit --- labor savings.  We didn't have to haul straw onto and off of the truck, onto the wheelbarrow, and then spread it in the garden.  Instead, I just raked back what was left of the summer mulch, scattered oat seeds on the ground, and lightly sprinkled a bit of the leftover straw back in place to help the seeds stay moist until they germinate.  After an hour and a half of light gardening, over 10% of our growing area is off my agenda until spring.

Before you go out and buy your own 48 pound bag of oats, you should be aware that oats dependably winter-kill only in zone 6 and colder (although parts of zone 7 may see the same results, depending on the severity of your winter.)  No matter where you live, you need to plant the oats early enough that they are well established before cold weather hits, which means you'll have to come up with some other mulch in garden gaps that come open later than a month before your first frost date.

You may also have to deal with weevils in your grain --- little insects that hollow out the seeds and prevent them from growing.  I eked out my 50 pound bag for a solid year, but I noticed that the last beds I planted in early August didn't come up fully, and a little investigation turned up lots of insects in the seeds.  For best results, only buy as much oat seed as you'll use this year --- most feed stores will sell you less than a full bag if you ask nicely.  On the other hand, if you put on your thinking cap, you might find uses for the full 50 pounds.  I used over half of my bag in one morning of profligate sowing --- the bare chicken pasture should be green again shortly!