Cover crops are a confusing topic for most gardeners, and no wonder. Most books expect you to plow them under. To gardeners, that doesn't sound doable. But new research shows that soil-building comes easier than that: from roots.

Of course, the top growth is important; preventing weeds alone is a huge benefit. And preventing soil loss.  But out of sight, the roots do much more. Like opening passages for oxygen, feeding earthworms--and dying.

When the tops are cut, the roots die and turn to compost right there in the soil. Compost that you don't have to haul, turn, or shovel. And we aren't talking small amounts here. Winter Rye makes 380 miles of roots per plant. The most fertile soils in the world are grasslands, where the roots grow and die in the soil year after year.

What to Plant? Let Nature be your guide.
Meadows and prairies have a mixture of grasses, legumes, flowers, and taprooted plants. The famously fertile topsoils of the Midwest were built by such plant communities. Use that soil-building synergy in your garden. Your mix should include:

•  A grass (grains are grasses) like wheat, rye, or barley.
• A legume, like vetch or clover.
• A tap-rooted plant like California poppy, chard, or mustard, to improve water absorption, bring deep-buried minerals to the surface, and open the way for crop roots to follow.
• Some flowers keep beneficial insects around--alyssum, calendula, arugula, poppies, cilantro, and chervil work well.
• Agricultural mustard to inhibit fungal diseases like fusarium, and add sulfur, an important nutrient for healthy plant growth.

 
Timing is important
The size of the root system depends on when you plant.  It's best to sow cover crops 2-4 weeks before your  first fall frost. *  Don't be surprised if the plants don't get tall--they will be busy underground. In tests, crimson clover that was was only 2 inches tall by November nevertheless had roots 12 inches deep, with many nitrogen nodules already fertilizing the soil. Rye only 6 inches tall had roots 20 inches deep. All winter, the roots will be holding your soil, providing channels for water absorption, and adding tons of organic matter to your garden.

But how can you plant cover crops when the beds are still full of summer plants? Here are some options:

• Broadcast the seed of your cover crop while the existing crop is still in place. This is easiest if the crop is fairly upright, but possible for most. It's called undersowing. Clover is a great crop for undersowing; it doesn't need as much sun as grains do, and the small seeds don't need to be deeply buried.
• Are your summer crops still actually producing? If they aren't giving good harvests, move on. You'll make spring planting easy by building the soil and preventing weeds now.
• Sow winter rye and clover into any empty space, even if it is not directly in the bed. They will take light foot traffic, and hold the soil during mud season. Great compost material, too.
• If you have to leave a few beds until late, sow rye and mulch it lightly.

Don't forget pots and containers.
A low-growing, cover crop prevents your expensive soil mix from getting washed away or taken over by weeds. Calendula, poppies, salad greens, clover, and peas are great for this. If you aren't using the pot, cover it with its saucer to keep weeds out.

*You can find first and last frost dates online. Here is one place:
https://www.almanac.com/gardening/frostdates

Tomatoes are coming in at my place and while I probably don't have to tell you how to enjoy tomatoes, I thought this was a good time to remind you of some simple ways I love.

Everyone has recipes for cooked or canned tomato sauce; I won't add to that stack. These are my favorite preparations for enjoying that fresh, fresh summer flavor and keeping it for winter.

Raw: hot-weather lunch
My favorite lunch, dinner, or snack this time of year. Grate, smash, or chop some garlic, add it to olive oil. 1-2 Tbsp oil per person is about right. Add a pinch of salt--this draws the flavor out of the garlic, (and incidentally protects you from botulism if you leave it at room temperature.) Slice a bunch of tomatoes, tear up some basil and some fresh mozzarella. Chop some Italian torpedo onions if you like them. Mix it all up and mop up with crusty bread. Ciabatta is good. Some people add balsamic vinegar.

Lightly Cooked: quick pasta dinner
Put 1/3 to 1/2  lb pasta on to boil. While the water is heating, chop up  sweet red pepper--one big bell, or 5 of the small Italian type. A hot pepper if you like. Saute in a skillet with a couple of tablespoons of olive oil. When they are half-cooked (color has intensified but not soft yet) add 1/2 onion, chopped; a sprig of rosemary; a couple of sage leaves; and a few stems of thyme. If you have fennel, chop and add 1/2 cup of the bulb or a pinch of the leaves. Sprinkle on a pinch of salt as they cook. When the hard veggies are soft, chop or tear up 3-6 tomatoes, depending on size. (Last night I used 3 huge paste tomatoes torn in pieces.) When the juices are bubbling all across the pan, add a handfull of fresh mozzarella, torn up, or 1/4 cup grated parmesan. Put on the lid and take off the heat. (If you use very juicy tomatoes, cook it in an open pan until it thickens a bit. THEN add the cheese and turn off the heat.)
When your pasta is well-drained, put it in a bowl, dump on the sauce, and stir. Serves 2.

Roasted: add flavor, subtract skins
Roasting is a great way to give tomatoes an intense, smoky-fresh flavor to go with main dishes or over pasta. But is also a perfect way to get the skins off for canning or salsa. And honestly, which would you rather do--sit with a cold drink watching a barbeque fire or stand over a hot stove in August?

Getting the skins off by roasting is no more difficult than blanching them in water, and is actually faster, because I can fit so many more on the grill than in the pot. Best of all, this adds flavor instead of diluting it, and subtracts water instead of adding more to an already too-juicy product.

For easy, fast roasting, and wonderful flavor, roast the tomatoes or peppers on the barbeque grill. (I usually cook meat on the grill and then fill the grill with tomatoes, tomatillos, or peppers and put on the cover, because I like a very smoky flavor. For a less smoky flavor, leave it open. Either way, you need coals, not a roaring fire. Turn the peppers or tomatoes till the skin is blistered and loose on all sides. This is much more fun to do outdoors than standing over a stove, and faster, because the grill holds a lot.

You can use the broiler in their oven instead of a grill, or the traditional dry griddle on top of the stove. Same procedure—turn until all sides are blistered, loose, and browned. Use medium heat for chiles and low heat for tomatoes. It is OK if the tomatoes crack open. Remove them to a plate. As soon as they can be handled, take off the skins with a paper towel, under running water, or just peel off what comes easily with your fingers.

This is my preferred start when canning tomatoes for salsa or sauce. It gives the sauce a delicious smoky overtone that doesn’t need meat to seem extra rich and savory.
It is the easiest way to prepare them for freezing too. Roasting replaces the blanching step in freezing. Just cool and put into airtight containers. If you like, add a tablespoon of olive oil and a basil leaf. You can pull them out of the freezer  all winter.