Not much will cover crop in after frosts have started. Most seed needs at least some time to sprout and grow in a bit before the cold kill off. But field peas, some annual clovers, hairy vetch, and winter rye can sometimes work fairly late. Especially if you get a nice warm stretch for a week or two after the first frost. Some of these can pop up in the spring too, like wintersowing works. You can also try early spring cover crops.

There are 4 grasses that will meet your needs after the tomatoes are gone and a good soil builders with winter Rye being the best and has the quickest growth. The others are winter barley, winter wheat and winter Triticle. All are nitrogen scavengers so will need to be amend with additional nitrogen when planting the tomatoes.

Winter Brassicas can plant late in the season after tomatoes but growth rate is slower than the grasses and a poor soil builder, but will scavenge less nitrogen than the grasses.

Behind the lettuce and Kale, well you can plant Kale, which is used as a cover crop and a good erosion control and soil builder, and just let it freeze out. Or you could plant Winter field peas (Pisum sativum subsp. arvense) which is a good soil builder and nitrogen source and also let them freeze out.

You could also replant lettuce for a fall crop. Plant when the soil temperatures get down, possibly to 70°F. I'm guessing maybe mid August for zone 5.

I have never planted a cover crop for soil building before. I thought that eventually the crop has to be turned into the soil, in order for nutrients to be added.

Right now I have lettuce, kale, swiss chard, and spinach growing right in front of the tomatoes, and allysum right behind them. Off course we are consuming the veggies slowly. I was planning to re-seed the kale and other vegetables for a fall crop and consume themAnd clean out the allysum once dead. Are you suggesting just to leave the veggies and let them freeze, but not turn them under ?

While the veggies can be a good fall crop, and some can even overwinter like kale and chard... I would not try to use them as a cover crop. Yes, the veggies will break down and release nutes after you turn them under- but I feel using a veggie crop as a cover crop kind of a waste of food resource. Cover crops are for feeding the soil more than feeding us. Though one can harvest the seeds of winter rye for grinding or field peas for soup, the majority of the plant is turned under to amend the soil.

I'm not sure what you need in your soil- you say hard and heavy, but also say loamy which should be a rich and fluffy tilth and not hard or heavy. So not sure if you are trying to feed the soil or amend the tilth or both.

i tried this once ... and frankly.. ruined my veg plot forever..

not all the seed of the crop sprouted the first year .. and was nice enough to hang around for a decade after i had strewn it ...

i had to move to solve the problem..

imo.. dont do it.. just go buy a small truck full of a good compost.. and properly work it into your soil.. and get that al done by fall.. so you will be all ready to go next spring...

ken

I have done as Ken suggests many times. But you can do both. Replant veggies and when they freeze dig them in with the truck load of compost. I'm assuming your soil won't freeze for the winter after the first freeze.

My error, sorry, our soil has lots of clay ( not loam ), is quite heavy, with a tan color, not the rich almost black fluffy soil I had envisioned. After removing the grass a load of triple mix was tilled in. We were told that their triple mix was a premium quality, not requiring any additional compost or cattle manure until the 2nd growing season. Big mistake, the soil below was a heavy clay soil, and the triple mix also had lumps of clay and peat moss ( which gets hard) amongst other things. After several rains the soil gets super hard and crusty. The tomato and pepper plants just sat there for about a month after transplant, not doing anything much ( hopefully growing roots ?), but after a month and my hand cultivating the soil around each plant and adding fertilizer they started growing and look healthy now.

I was hoping to build a better soil to grow our vegetables in terms of texture and nutritional factor, without adding much bought compost. The last bag of composted cattle manure I ordered also contained a lot of peat moss which I did not really want. I have had problems with compost before... it may not have been sufficiently aged, the seed from some weeds that the animals had eaten grew in our raspberry patch forever.

Our soil has lots and lots of very long healthy worms ( robins are lining up and nesting nearby ). Grubs too which I did worry about, but so far saw no damage to the veggies...We have leaf trees ( maple etc) and large blue spruces, pines and cedar. Been collecting leaves, mulching them and using them in the garden as mulch. Using pine mulch under the trees to keep the weeds at bay. We also have a big lawn, and hubby is now collecting clippings in bags. Recently I acquired a small compost bin mostly for our food scraps, which he finds complicated. Suggested to also build a bigger one for grass and leaves, but there is strong resistance here....if only I could convince him to just dump leaves and clippings in a corner at the back and leave them there all winter, exposed to rain and some sun... would this work?

Can spent tomato and squash plants be added at the end of the season? Although, the squash plants seem to be infected with cucumber bugs or squash beetles, maybe they should be destroyed instead.

Winter crops incl. radishes? Last year it started to snow end November, the lawn was covered with snow till end March, some more came in April....

Maybe I should forget about cover crops and use what we got?

Beesneeds, how do you make a fermented fertilizer with tomato plants ?

Test for drainage problems, slow drainage would indicate anaerobic conditions which would cause plants to grow slow. Soil that drains to fast will parch many plants with high water demand like tomatoes, and shallow rooted plants like onions and result in slow growth even if they’re getting regular watering.

Dig a hole about a foot deep and a foot wide then fill with water. After 12 hours fill the hole with water again and see how long it takes to drain. if it drains less than 1" an hour you have slow drainage. 1 to 3 inches an hour is ideal, and over 3 inches and it's starting to drain too fast.

If you use herbicides on your lawn you shouldn't use it in your garden.

Dumping leaves and clippings would work just fine. “Herbicides commonly used on home lawns persist in the soil from less than one month up to 12 months, depending on the chemical. If some treated clippings are mixed into a compost pile, they will decompose more rapidly in a properly maintained pile than in soil.” https://extension.missouri.edu/publications/g6958 So providing the heap is left for some months you can safely use the clippings in your compost. Better still, don’t use herbicides.

There is nothing complicated about composting and the bigger the heap the easier it is. You can put kitchen scraps in with garden rubbish. No need to keep them separate. A bin can be as simple as a cylinder of wire netting or three pallets wired un a U shape. Or just a pile.

There's a lot of different ferments one can make, and a few ways to do it. Simplest one is anaerobic ferment- this draws out nutrients and minerals, but does not promote and can even kill bacteria and microbes. Take a covered container, fill with chopped up plant, fill with soft water, toss a handful or two of leaf mold or finished compost on top. Put lid on and set aside to turn into rank swampy goo water. Make sure where it sits it does not fully freeze. Strain water, and then use diluted in your garden. Something like a tomato plant ferment can be started in the fall cleanup, then sit till you start applying in the spring into summer. If you make weed ferments in the summer it can take just a couple weeks for a bucket to turn fetid. I tend to do this kind of ferment most. An old T-shirt with the neck and arms sewn shut makes a good strainer in a bucket. and the whole strainer can be pulled out and tossed in the back compost pile once a ferment is done. This kind of ferment also kills bugs- squash bugs drown and have no escape from a closed container of rotten water. It does not necessarily kill off disease and fungus though, so thats why crapped plants go elsewhere.

Ferments can also be done aerobic by putting a small bubbler into the container and using a lid that breathes. This draws out less nutes and minerals, but helps encourage the growth of bacteria and microbes. Oxygenating the water also tends to reduce the smell factor since it helps relese the smelly gasses from the ferment. I don't tend to make this kind of ferment at this time, though I have the ability to do it. If I'm running a bubbler it's more likely because I'm growing something than breaking something down.

Ferments can also be done using brown sugar or lacto starters like grain waters or milk, but those can be kind of advanced for folks not used to doing ferments.

Yes, the leaves and grass can just be left in a pile. Cold composting takes longer than hot composting AKA turning piles does. I make compst cages out of three foot wide 2'x4' wire mesh (I make 6' growing towers and break them down when they get damaged). It's where all the crappy stuff that shouldn't just be tossed in the gardens goes. Leaves and mulch grass goes into the gardens. Takes me a year or few to really pack a cage full. Then I top them off with good growing dirt and use them as really tall raised beds. I line the cages with recycled paper or cardboard as I fill them to keep them contained.