Hi All, Zone 5 here. I just cleaned up my raised beds. I have wonderful soil, a one time gift, so it is very precious to me.. Should I put a thin layer of mulched leaves over it for winter or just leave it bare? All advice welcome. AnnFran
I don't do anything to my beds in the winter. I usually plant some fall squash and cukes and when they die out, I pull everything out of them and give them a good tilling. We have a winter grass that will cover them if left untilled, so I till them occasionily to keep them clean. After the first of the year, I add compost and get them ready for spring.
Mulch is good! And a leaf mulch will break down and enrich the soil. Chopped or aged leaves will enrich the soil faster than whole leaves.
Before you lay down the mulch, consider adding finished compost or manure or coffee grounds. Since it will break down and soak in somewhat over the fall, winter, and early spring, you don't even need to mix it with the soil ("turn it under") ... though I do, to speed up it's return to the soil..
For good soil to stay good, you have to feed the micro-life and worms that maintain its structure and fertility. They eat organic matter to supply their energy and nutrients, and will exhaust the existing humus and compost in your soil if you don't replace it.
If you don't have a compost heap of your own, you might try to collect more leaves next year and pile them deeply. Chop them up if you're energetic. If you feed that pile some coffee grounds and kitchen scraps (or manure), it will decompose even faster.
Next spring and fall you'll have finsihed compost, even better than mulch.
I shredded six 40-gallon contractor bags of oak and pecan leaves this past Saturday, and layered them 4"-6" between my raised beds, and along my fence line where more raised beds will eventually sit. I wet the layers thoroughly to ensure the promised rainstorm on Sunday would be able to penetrate the layers and reach the ground.
I didn't even think about spreading coffee grinds, since I was trying to beat the rain. Will double back and spread coffee grinds at some point. Anticipating really good compost in those areas by the time I construct more raised beds!