Ok...what are good non-legumes?

Late June would be sowing time.

What about Summer Alfalfa? Sowing by 7/1 and tilling around mid-November. Would have 120+ days of growth.

I planted oats & field peas in late June this year. They are about a foot tall now. I plan on turning them under before I plant garlic in October.

Why does it have to be tilled in in the Fall? I mean the longer you can let any cover crop grow the better. If you need the space for growing something else, fine. But if you aren't going to plant a fall garden and don't need the space then why can't you just leave the cover crop growing? You can even turn a single row over right through it and plant.

Many of the cover crops are quite frost/freeze tolerant and don't need to be tilled in until late winter or even early spring as soon as the ground can be worked. How big and area are planning on seeding?

Dave

I don't own a tiller, (I have to rent one, and it gets expensive), and fall tilling makes early spring planting easier.

50 X 50 max

I guess I'm also thinking it's better to have it somewhat decomposed over winter, vs having fresh, uncomposted material in the soil at planting time.

Tilling or turning - same result. You said "tilled" so I assumed you meant tilled. Either way it has to get mixed into the soil to a degree so it is just a matter of when it is done.

But bare soil in winter is an open invitation to weed seeds and topsoil lost. No soil improvement is happening. If nothing else, cover it with a layer of compost.

But the ground cover, if left in place as long as possible, will be killed off by a good hard freeze and will begin to decompose in place. When that hard freeze comes depends on location but in zone 7 it often can be well into December.

That way the soil residents do at least some of the work for you. And as the spring thaw develops and melting snow and winter rains can carry the nutrients down into the soil.

If whatever you choose to plant gets tall enough to mow in the fall before a hard freeze those mowings, if left in place, coupled with the later new growth can get you 2x the benefit by spring. Un-decomposed carbons can pose a problem but green manures such as high nitrogen cover crops pose no real planting issues.

Bottom line - there is really nothing to be gained by early termination of a cover crop unless the space is needed to grow something. Rather letting nature run its course can provide much soil improvement and often less work for you. You can find much more discussion about all this over on the Soil & Compost forum.

Dave

Cover crop discussions

concur with Dave. do not till it. Specially if you plant non fibrous plants, buckwheat and daikon, the CC will melt into the soil, disappearing completely. Also, one of the most useful discoveries of the last decade is that a thick, non legume cover crop produces similar amounts of N as a legume. It is because of the superior bio-mass, and all those bacteria which pull N out of the air to digest the dead (winter killed) residue. Also the longer roots of more vigorous crops go deeper and bring more N back to the surface.

I am using oats, buckwheat, daikon, sunflower, vetch, which are my regular cover crops, and fenugreek as first timer (an experiment). of these only vetch will survive the winter, but it will get smothered by leaves next year when i plant potatoes in there.

Ok. THIS fall, I'm tilling because I'm expanding the garden and liming the new areas, and need time for the lime to work before spring. Native pH is 5.2.

Starting next year, I'll try these suggestions.

Of course, around here, any ground that lays bare for more than a few weeks during the growing season ends up covered in Japanese stiltgrass and wild violet.

right. You do not really have a choice: you either plant your own weeds (and I assure you, some CC are quite weedy in nature) or nature will do it for you. By tilling, you will bring up the seeds nature needs to cover your garden. It is well known that cover crops eventually eliminate weed seeds, but that only is valid for the seeds at the surface, exposed to many predators and unable to germinate due to competition from CC. In other words CC weed your beds, but only if you also no-till. Seeds underground are much safer and last decades until summoned to the surface.