Thanks Dave. I was thinking of doing just the spots that are empty. Not all crops will be harvested as I have kale and chard for instance that will stick around all winter since we don’t get many freezes.

I’ll see if I can plan better but between rotating crops from bed to bed each year, planting companion plants together and in general fitting everything in, it’s not that easy! Still learning something new each year.

good question. This was the first year I planted a cover crop and it's only on one bed. I'll use Dave's suggestion for doing at least one bed every year. Right now a second bed needs to get planted with hard neck garlic. Another bed still has Asian greens and beets. Etc. I also tend to procrastinate about cleaning up a bed. The summer squash bed could have been cleaned up many weeks ago.

Except for nitrogen fixing by legumes, it's never been entirely clear to me about the value of cover crops versus compost. Both add organics to the soil. The cover crops, when dug in, are basically composted in situ. Am I missing something? True that if you want to add organics to the soil, cover cropping involves somewhat less effort. In both cases you need to till, but for cover crops you don't have to spend extra effort managing compost production.

"Cover crops" have a wide range of varieties and each type provides different benefits to the soil besides only adding organic matter. Some such as mustards can be used to control nematodes. Daikon radishes not only add organic matter when they rot, but also mine nitrogen from deep in the sub soil, help to loosen compacted soil, and provide channels in the soil structure for the following crop's roots to follow. Buckwheat is a good miner of phosphorous in the sub soil (just don't let it go to seed!).

I find that the tillage radishes [daikons from Fedco] make an excellent cover crop for me. They only get sown in beds cleared by September 6th here in the north. They are super for keeping weeds out in the fall and early spring. They rot down very early in the spring and do not interfere in spring planting.

Like Dave said, Marc, undersowing is typically done when you still have vegetables growing in the ground. Be mindful of how much time the cover crop needs to grow, because they can't be planted at anytime. It also depends on where you live. Where I am, I can't plant a cover crop now because it's too late. Some also don't survive our winters, so they need to be planted early enough so that they can get established before a winter kill. I'm actually growing oats right now, which can't survive below 20°.

Cover crops have many different values, like Jack mentioned. Some of the most important, IMO, are preventing erosion and leaching of nutrients. Cover crops in the grass family are great for this because they have large, fibrous root systems. The soil should never be left bare, whether you're mulching your beds for the winter or growing a cover crop.

This site gives you a lot of information about cover crops. http://www.sare.org/Learning-Center/Topic-Rooms/Cover-Crops

I got a Green Manure Mix from Johnny's Seeds. The peas look strong and healthy and so does whatever else is growing in the mix. I think this will also help keep the bed weed free in the spring. This ready-made mix is comprised of winter rye, field peas, ryegrass, crimson clover, and hairy vetch. Vigorous late summer growth provides winter erosion control. The peas, clover, and ryegrass will winter kill to provide organic matter and soil cover. The hairy vetch and winter rye will regrow in the spring to provide nutrients for crops to utilize. Because the seeds of this mix vary in weight and size, it is best seeded with a grain drill.

Nice mix! Just watch out in Spring with the vetch. It's supposed to be killed right as it starts flowering(for optimal nitrogen fixation) or it will go to seed and become a nightmare to get rid of. I planted vetch 2 years ago and I'm still pulling it out every so often. What do you plan on growing in that location following the cover crops?

Well, in principle, cover crops can't actually add any elemental nutrients to the soil, because they're growing out of that same soil. As to loosening compacted soil and providing channels for future roots, that's precisely what compost does. That's the whole idea about improving soil friability with compost. The idea that cover crops can "mine" nutrients is an interesting one, though. Had not heard that. The idea that the fibrous root systems of cover crops prevent erosion and leaching of nutrients is also exactly what compost does. Compost is precisely fibrous organics that have not yet completely degraded. When you till the compost in, the fibrous organic result is exactly like when you till in the cover crop. Sorry, I just don't see it.

Now, I guess if you do no-till, and just leave the cover foliage cut on top as a mulch, you've probably done more good for your soil than just dumping compost on top of it.

I don't do cover cropping, mainly because my growing season is pretty much the whole year, but it would be nice to understand it better.

Nitrogen-fixing cover crops take atmospheric nitrogen(N2) from the air and fix it to their roots via bacteria. While the plant itself may use some nitrogen in the soil, the release of nitrogen is far greater than what was previously there, after the plant dies. In fact I think vetch can produce upwards of 100lbs of N per acre.

I still use compost and I always will. It does improve tilth and helps form soil aggregates, which increases water infiltration and reduces erosion. It has enormous value. Though leaving it exposed to the elements would probably degrade its benefits rapidly. For those who can't compost, whether they don't have the room or composting materials, this would be a great alternative.

Dan - certain cover crop roots such as Daikon Radish go much deeper than most any other crop or than one would normally amend with compost. Sure, worms may eventually incorporate the compost much deeper into the subsoil but not nearly as quickly.

Here is a link that explains tillage radishes much better than I ever could.

Tillage radishes

OK, I was agreeing that legumes as cover crops offered nutrient value compared to compost. I said that in my original post. That's abundantly clear. I'm trying to understand what other stuff does for you. Deep rooted Daikon radishes sound like a nice idea, but those aren't what I'd call a "classic" cover crop. It would seem to me that having a lot of organics bound up in dense and slowly degrading roots like radishes might not be optimal, however. I'm not sure I want to plant in a bed full of radish roots.

I'm not being skeptical about the value of cover crops, but the relative advantage compared to compost really isn't obvious. In fact, the biochemical distinction between that and compost isn't that obvious either. Hey, if you don't want to regularly moisten and turn a compost pile and then haul compost to your garden, cover cropping seems like a fine idea. But I'll bet I can get more organics into a bed with compost than I can with cover crops.

Very good link LoneJack. I have never noticed any smell from the radishes in the gardens...this is my fifth year.

I like the smell of Daikon radishes. I just don't necessarily want any big tuberous lumps in my soil that I'm planting in. But I guess with a powered tiller you could just grind 'em up. I'm not going to be hacking away at Daikon radishes with a shovel, however.

Ah, so the radishes self-decompose. That's handy.

But I'm concluding that cover-cropping, at least with grasses, doesn't offer a small gardener that much. I can understand that for a large farm, dragging many truckloads of compost in to amend is a huge task. Having the large plot self-amend with a cover crop is thereby comparatively efficient. But for a small plot, dragging a wheelbarrow or two of compost in isn't that big a deal, and you'll bring in more organics that way than you're likely to grow there.

I am so glad I am reading this. I don't have the space to compost myself in the city so I buy bagged compost. I have only used my raised bed once for tomatoes and a cucumber plant this summer. Right now I have a radishes planted for a quick fall crop. I don't think I have to do a cover crop this year. My plan was to add compost and leaves for mulch when I harvest the radishes. Is that good enough til Spring. There is not much time for a cover crop when I am still using my bed for food. Should I be doing something differently? Please let me know. Any advise is appreciated. Thanks in advance.

Patti - a layer of compost and heavy mulching of leaves is perfect before the winter. That's what I use when I'm not growing cover crops. Do you just have the one bed? What are the dimensions?

I agree. These posts have been informative. Chris, thanks for the advice on hairy vetch. I haven't decided what I will plant in that bed next year. Last year it had summer squash and zucchini. This year I foolishly planted some old bush bean seeds that never germinated. I think there was an attempt to plant something else but that failed, too, with some soil disturbance that might have been wild turkeys using the bed for a dust bath. The green manure cover crop seemed like a good idea at that point. While weather was unusually warm and sunny this fall, I was doing other things and neglecting the garden. Now here in NH it's turning cold and rainy and the leaves in our driveway should be gathered and put on the vegetable beds. Reading what I should be doing is the first step.

Patti - I am in the same boat as you in that most if not all of my beds are in use from early spring until sometime in October if not even later. All of my beds get at least one application of compost every year and often 2. Sometimes it is applied in the late fall, sometimes between a spring crop and and a fall crop and sometimes in the early spring a few weeks before I plant. It all depends on when I have the finished compost available and what I am planing to plant in the bed and when.

All of my beds also get a layer of shredded leaves applied in the fall as a winter blanket. I plan to incorporate a fall cover crop rotation into a bed or 2 going forward possibly using a mix of legumes and tillage radishes to gain the benefits of both. In the past I've used both buckwheat and tillage radishes to mellow the soil in new beds of native soil and it worked very well. I have no plans to break any new ground in the future but you never know.

Chris, I do just have one bed and it is 4' by 8'. This is my first year with the raised bed. I have tried unsuccessfully to grow veggies in pots due to many troubles. This year I decided to invest in the bed. It worked out great. I didn't get it in until early June so I did not do a spring crop. I did 2 tomatoes and 1 cucumber in the bed and that was crowded by the end of the season. I want to do the best for the bed to prepare for next spring so I have been reading for advise. I have read so many people's woes and all the advice given dating back years. I enjoy the garden and flowers from June til October. There is nothing like a homegrown tomato in my eyes.

Patti, I'm glad you gave the raised bed a shot! Definitely a great way to grow. Having one bed does make the use of cover crops a little more difficult, unless you grow a "living mulch". I did that with one of my tomato beds this year. I undersowed clover in the Spring and then kinda turned it in at the end of the season. Using compost after every planting might make more sense for you and adding organic matter as a mulch throughout the year(chopped leaves or untreated grass clippings). What issues did you have with pots? I grow a lot of my tomatoes in 15 gal pots. I'd prefer to grow everything in the ground, but that's just not an option.

You're right, homegrown tomatoes are unbeatable!

Chris, I had many problems with blossom end rot and just drying out with my potted tomatoes and very little production. I would water in the am before work and they would be so dry at night by 6 when I came home. I have read a lot of posts in the "growing tomatoes" portion here and I think it was the dark pots and the place I had the pots in my yard. It was too much heat all together. I grew peppers in pots this year in different colored pots on my little patio near the garage and my plants grew tall but the peppers would grow nice and then before I know it they would have a dark spot on them, like a bruise. I cant say blossom end rot because it didn't look the same as on the tomatoes. I kept the pots evenly moist and had straw for mulch so I don't think it wasn't enough water. I will give up on the peppers and get them at the store for the amount I got from the three plants it just wasn't worth it to me. I already purchased some zucchini seeds for pots and will try them next year. I will only do one or two plants. I was going to try to grow my cucumber plant in a pot as well next year and leave the bed for the two tomato plants so they can have the entire bed. Gardening is sure is a live and learn experience. I am so happy not to have had many of the diseases and pests that the people talk about here on the forum. I was lucky for having only a bit of downey mildew on the cucumber but once I treated the plant it grew until the middle of October and it produced many fruits. :-)

Oh it's a live and learn experience alright! haha If you're persistent enough, you get to reap the benefits. So many knowledgeable people here that frequent this forum. While I do read a lot about gardening, it's not the same as getting the advice from someone who has experienced it. That goes with anything I suppose. Once you become more confident in your growing, you'll expand and try more things.

Growing anything in a pot requires more maintenance. The first mistake people make, and I've made in the past, is not using the correct pot size. Next mistake is not using the correct potting medium and third is usually lack of supplemental feeding. Growing in pots definitely makes more sense for you, since you have limited space. Yes, sometimes you need to water pots twice per day :-/ Especially smaller pots. Since pots need watering so frequently, the nutrients inside usually get washed out, which means you need to give it more. I use diluted fish emulsion for that.

Anyhoo, I don't want to turn this thread too far off topic, but don't give up!! Also, you can get more than 2 tomato plants in a 4'x8' bed! You can put 4 comfortably in there and I would even go to 6 myself. Stick around this forum and you'll learn A LOT from everyone. Happy growing!

Hello Tranquil, I've spent years building my soil. I still do, its a continuous process. I always have at least an 8' x 8' bin of compost cooking. That being said, a cover crop is an excellent way to offer mychorrhizal fungi to your plants. Some seem to get hung up on choosing one method over the other...compost or cover crop. I choose both as they both offer different benefits. Compost is probably the best bang for the buck, but a cover crop helps too. As an example I like to get mychorrhizal counts up using a good mix of winter wheat, clover, vetch and radish as it significantly increases AMF. I recently read an article in a journal on microbiology that indicates Zinnia Flowers allow for large colonies of mychorrhizae too. It doesn't get much easier than growing Zinnia's! I found that Ebay of all places is one of the cheapest routes for seeds nowadays. It's even cheaper than my local CO-OP. I buy in bulk and store the left-over seeds in sealed 5 gal buckets. I know this didn't exactly answer your question as where I live is zone (5b) doesn't allow for much opportunity in the winter for direct comparison.