Fall Cover Crops


Next Years early potatoes...

Next Years early potatoes...

 Several weeks ago I wrote an atypically lyrical bit on Fall and my gardens.  I love this season, and now I would like to pass on a bit more of the practical bits of what I have been up to – tucking my beds in for winter.  My preferred method of soil stewardship is cover-cropping. Last year I used alot of straw in my home beds after reading Ruth Stout and Lee Reich and their deep mulch gardening.  It worked very well – my garlic was essentially weed free for the entire season.  And I will continue to use straw mulches on my permanent home beds.  But out at the market garden I am using cover crops almost exclusively.  Above is a shot of a cover cropped field that had been in Garlic, and will be an early potato planting in 2009.  This field still has a fair amount of perrenial weeds -primarily quack and thistle so leaving it bare is not an option if I am to turn the tide.  Rye/Vetch is a great standby for both nitrogen and biomass, but I hope to plant this field in April -too early to let the vetch really fix nitrogen and the thick masses of rye roots decompose.  

Oilseed Radish and Field Pea Cover -5 weeks

Oilseed Radish and Field Pea Cover -5 weeks

So instead I wanted to put in a “winter kill” mix of annuals that would put on biomass in the fall, but be ready to plant in early spring.  For this I choose a mix of 4 crops: Oilseed Radish (good root mass and nematode protection), Field Peas (nitrogen and cold resistance for late growth), Oats (biomass and root structure to outcompete weed roots) and Buckwheat (quick cover to let the peas and oats get going).  This worked fabulously -the buckwheat sprang up quickly to shade and stunt the resprouting quack, only to be killed off in the first mild frost 3 weeks ago.   This was timed perfectly to let the radish and field peas to shoot for the last vestiges of Fall Sun.  Despite some 28 degree frosts, all crops are going strong, with only some minor frost burn on the radishes.  The plot is a dense mat of greenery about a foot thick that will be killed off by Christmas to blanket the soil for the winter.  Come spring it will be easy to till under or transplant through.


3 Week old Rye/Vetch

3 Week old Rye/Vetch

On this years potato patch I did plant Rye and Hairy Vetch.  This plot will hold melons in 2009 which matches very well.  Melons and Squash will not be ready to plant until June, leaving plenty of time for the rye/vetch cover to be mown and begin to decompose.  My hope is to plant directly through the rye stubble; if the mowing is timed correctly it will not resprout. Also, the decomposing rye is naturally allopathic (prevents weed germination) which will not inhibit transplants, and the thick mat of straw will help reduce damage to the growing fruits.  That is the hope, we’ll see how it works.

My choice to cover crop on the larger market gardens was made for a variety of reasons.  First, there are some very real practical ones – laying out a 4″ thick mat of straw takes alot of straw.  I don’t have a bale blower so labor would be extreme, and straw bales are going for $3.50 up here (none of it organic) and it would have been $200 to cover my beds, rather than $30 in seed.  Secondly, I would rather not import 5000+ pounds of organic matter to the site if I can just grow it in place, cycling the nutrients in house as it were.  Finally, from a soil ecosystem perspective, I like to have living roots in place as much as possible to foster the soil flora/fauna that I will need next year.  

Mulching works wonders on the soil as well – the soil under my garlic this year was incredibly light after the worm population exploded while feasting on the year old straw mulch.  One hope next year is to grow my own mulches with a 3000 sq ft crop of sudan grass which can reach 4-6′ tall and produces several cutting annually.  I tried this in 2008, but the resident chickens ate all the cover crop seed before it sprouted (I planted too early) so I will need rethink it a bit in 2009.  The Sudan Grass mulch would cover my tomato and potato rows early in the season, and the later cuttings will blanket the Hoop House and other beds.  

Later this week I will post the 2008/9 picks of the Hoop House which has been moved and replanted.  Stay tuned!


4 Responses

  1. Great little site and very intresting stories keep up the good work. would love it if you got the chance to look at this site and give me your opinion http://www.gardeningcareblog.com

  2. Hey Rob:

    Just a note to let you know we planted sunchokes on your recommendation this spring. Our plan was to use them for pig forage. You recommended we spare them from the pigs for the first year. They roared up twelve feet or so, and planted a lot of nice white nuggets in the earth. I did let the pigs at one small corner of them just to see what would happen and they love them. Hoping to plant a pretty big patch of them next year and turn the piggies on them. Cheap pig food is good pig food.

    Enjoyed your cover crop piece, quick question: what’s the latest date you’d plant any cover crops? Been on the road a ton and probably missed the window. And if it’s too late, is it still better than nothing to do a fall tilling (this would be with a three-point tiller).

    Also, we’re talking mostly sod here. Some was a chicken run.


  3. Andy, checked out your site. Looks like you are up to alot of interesting things -keep up the good work!

    Mike, that is fantastic to hear about the pigs! Please let me know if that spot they grazed/rooted through comes up again in the spring – I would love to hear more!
    Without knowing your zone it is hard to make a recommendation on crops, but Rye and Vetch can go in any time. They will work their way in between frosts and will sprout in any winter thaws – not much to look at on top, but they will sink roots as long as the ground is not frozen. Crops like clover are best planted in late fall – they sprout early and will get a jump on weeds in the spring. Annual crops like oats are too late, and buckwheat can’t take even a whiff of frost. Our First Frost Date averages 10/9, and I just planted 3000 sq ft to rye this past weekend (10.26) and expect to see good things. One thing though, the later you plant the longer you will need to give it in the spring to get good growth. If you are worried about running out of time in the spring, try spreading leaves with a manure spreader or something which is what we do over our garlic and asparagus at the farm I am leasing at. This may be best for the sod – till then cover, then till again in spring. Can you run the pigs on it all winter with a moveable shelter?

    Tilling without any cover crop will only promote erosion – I don’t think it is worth the week or two you may gain in the spring by it drying out sooner. Plus being exposed will wreak havoc on the soil critters as they are uninsulated.


  4. OK, thanks Rob. All very helpful. We’re up here in Eau Claire/Chippewa County area, zone-wise.

    I will take your idea of running pigs over winter and stow it away…our current batch won’t cooperate as they have just recently been “repurposed”, if you know what I mean. October, time to smoke the hams.

    Again, thanks for the info you post. Very helpful to those of us only in the dabbling stages.


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