Tag Archives: southern peas

Cover Crops for Great Green Manure, Mulch, and More

By Ira Wallace

Warm weather and late April rains have our fall-planted crimson clover, winter rye, and Austrian winter peas growing like weeds and just starting to bloom.  As an edible bonus, the winter peas gave an abundance of sweet pea shoots to add to salads all winter and spring. The bright red flowers of crimson clover provide much-needed pollen and nectar for pollinators and other beneficial insects in spring.

To select the best cover crops for your garden, consider which functions are your priorities, the time of year, and how long the cover crop will be in the ground. Cover crops are important tools all year for filling in gaps between crops while also preventing soil erosion, suppressing weeds, providing habitat for pollinators, and improving fertility. Some even provide an edible bonus, for you and for pollinators. Here are some cover crop favorites in the Southeast.

Winter Nitrogen Fixers – soil fertility out of thin air.

  • red-Clover-2-GryphonClover (crimson, white, and red Sow clover six to eight weeks before your average first frost date. Clovers fix nitrogen in the soil and thus boost nitrogen for next spring’s garden. Mow one or two times when about half of the crop is flowering. Allow the residue to decompose for at least two weeks before planting vegetables.
  • Hairy Vetch– Sow hairy vetch six to eight weeks before the average first frost date. This vine-like, vigorously-growing, cold-tolerant, winter-hardy, annual legume adds nitrogen and builds soil organic matter. Hairy vetch grows well in cereal grain mixtures and is an excellent spring weed suppressor.
  • Pea shoot and Brassica Flower xaladWinter Peas (Austrian)– Sow winter peas four to six weeks before the average first frost date. Sometimes called “black pea” and “field pea”, this is a cool-season, annual legume with good nitrogen-fixing capabilities. Usually planted with rye, oats, or barley to reduce the chance of winter kill. Cut and turn under at full bloom for maximum nitrogen.

Winter Soil Builders and Subsoil Looseners – for the surface or deeper down.

  • Winter Rye (Cereal Rye)
    Sow winter rye six weeks before the average first frost date and up to two weeks after. A cold-hardy crop, winter rye will grow well into the spring. Winter Rye increases soil organic matter as it decomposes. Mow one to two times when at least 12 inches tall, or when half of the crop has immature seed heads. Allow residue to decompose for at least two weeks before planting vegetables.
  • Oats – Sow oats eight to ten weeks before the average first frost date. Oats are killed by the hard frosts. They form a winter surface mulch, preventing erosion and increasing soil organic matter as they decay.

Edible Cover Crops

Traditional gardeners in the Southeast plant a big bed of winter greens (turnips,  mustards, kale, and collards) to keep the garden covered and provide fresh eating until spring.  Plant this beautiful edible greens cover crop in August or September to build organic matter and provide healthy meals all winter long. Try a mixture of the old Southern favorites and contemporary choices like Seven Top turnip, Lacinato kale, Red Russian kale, Southern Giant Curled mustard greens, and Tatsoi.

If you are in the upper South or in the mountains, cover your winter greens with row cover or plant in a cold frame for winter harvests. Left uncovered in cold winters, the leaves will be too damaged for good eating, but you’ll have fresh new growth in early spring if winter lows aren’t too bad.

For more reason to plant cover crops read our Cover Cropping for Unpredictable Weather

 

Warm Season cover crops and filling in the summer gaps

  • Sorghum-Sudan Grass hybrid Plant in spring and summer, beginning after the soil has warmed and up until six weeks before first frost. This hybrid is unrivaled for adding organic matter to worn-out soils. These tall, fast-growing, heat-loving summer annual grasses can smother weeds, suppress some nematode species, and penetrate compacted subsoil.

 

  • pink-eye-purple-hull-webSoybeans (Edamame) and Southern Peas (Cowpeas)
    Plant in early summer through mid-summer, between spring and fall crops. Mow before pods have formed or when pods are still green and have not matured. These legume family plants can fix nitrogen for an added bonus.
  • buckwheat-webBuckwheat
    Plant from spring through early fall when the ground will be open 5 weeks or more. Buckwheat establishes quickly, suppresses weeds and attracts pollinators. Mow one to two times when half the crop is in flower and before hard seeds have formed. Will be killed by frost.

Although fall through winter is the most common time when gardeners grow cover crops, savvy gardeners include summer cover crops in their garden plans. No matter which cover crops you choose or when you fit it in your garden rotation, cover crops allow you to grow your own nitrogen and organic matter in place.

When to Mow or Turn Under Cover Crops

A lot of factors go into determining the best time to turn under or at least cut down your winter cover crop. To get the most biomass, wait until half of the cover crop is in flower but make sure to get it cut down and incorporated before it goes to seed. Some freshly cut cover crops like winter rye inhibit seed germination for the following crop. If you are planning to direct seed allow 2 to 4 weeks for your cover crop to decompose before planting. This same property can be an advantage in weed suppression if the cover crop is just crimped or rolled and left as a mulch for transplanted tomatoes.

Another factor to consider is when you want to plant the next crop. For early spring plantings you may need to cut and turn in your cover crops well before flowering and allow a longer time (maybe 3 to 6 weeks) for the organic matter to decompose before planting. You can speed up decomposition of the cover crop 1 or 2 weeks by sprinkling in some mature compost or applying compost tea to add beneficial soil organisms before turning it under.

For most home gardens you can cut your cover crop with a hand sickle or scythe and add it to your compost. This leaves the considerable roots to add organic matter and aerate the soil. You can also weed-eat it or mow it and just let it lay there on the ground as mulch or till it in.  For the home gardener, Roto-tilling  is the fastest and easiest way to incorporate your cover crops, but you can also spade in your crop residues the old fashioned way. Digging in your covers crops aids in faster decomposition and less nitrogen loss into the atmosphere.

 

Sustainable Agriculture Research Stations

Continuing our summer road trip adventures! Besides seed growers, we also visited with many vegetable breeders and researchers on our trip.  Here we’ll profile four organic and sustainable agriculture research stations.

North Carolina State University’s Mountain Research Station in Waynesville, NC (near Asheville) is up in the hills, and cooler and wetter than most of NC – a great place for tomato disease trials! Here, Luping Qu, Reuben Travis, and Jeanine Davis discuss how to measure the effects of diseases for their trial notes.

There’s a lot going at the Mountain Research Station. Besides tomato trials, we got to see melon and squash trials, stevia trials, hops trials, organic broccoli variety trials, and much more – here’s an overview of this year’s research projects. And that’s just the Alternative Crops and Organics part of the farm – elsewhere on the farm, there’s a big broccoli varieties trial that’s part of a multi-state project that aims, among other things, to find broccoli varieties that hold up well in the heat of the Southeast.

A great practice at the Mountain Research Station farm (and at many other farms we visited) is to plant strips of flowers and herbs — usually on the edges of fields, but sometimes in the middle as well. These flowers and herbs help attract pollinators and bug predators.

Jeanine is the co-author of Growing and Marketing Ginseng, Goldenseal and Other Woodland Medicinals. Her blog about the work at the Mountain Research Station is a great read. She’s a dedicated outreach person, and besides giving talks at the Carolina Farm Stewardship Association’s Sustainable Agriculture Conference, she regularly speaks at many conferences, including this year’s Heritage Harvest Festival at Monticello, September 11-12.

A quick stop was the University of Tennessee’s East Tennessee Research and Education Center in Knoxville. We were already visiting three different Tennessee farms that day, but there it was, only a couple miles away from Jonathan Buchanan’s Crooked Road Farm, so we dropped in for a quick look. Much of the farm’s work is giving young beginning farmers experience growing market crops, but we also got to see pepper trials, stevia trials, and – a great new vocabulary word – ratooning trials for kale and other crops in the brassica family. Ratooning is the practice of severely cutting back plants to stimulate new growth for later production. Okra growers in the Deep South often do it, so as to keep okra plants from getting 10 feet tall or more! Here’s a ratooned kale crop at the East TN Research and Education Center.


Next was the USDA’s U.S. Vegetable Laboratory in Charleston, South Carolina, with Clemson University’s Coastal Research and Education Center (CREC) nearby. Mark Farnham and Richard Fery with the USVL, and Brian Ward (at left below) with the CREC, showed us around. Here Mark talks about his work with breeding summer broccoli that holds up in July heat. Vegetable breeding is patient work – it can take planting out big fields of dozens of different breeding lines to find the best traits. This was July, swelteringly hot in Charleston, but there was some great looking broccoli out there – Mark’s hoping to release some of the breeding lines in the next few years!

Mark (at right below) is a brassicas guy; another recent project of his and Pat Wechter’s, Carolina Broadleaf mustard, is a leafy green bred for resistance to a bacterial leaf blight that’s become a problem in the Deep South. The USVL makes small amounts of breeding stock available to seed producers, so we’re hoping to line up some of our own seed growers for this one and have it in the SESE catalog in the next few years.

Richard Fery is emeritus plant geneticist at the USVL. He’s worked on many different seed crops over the years, mostly peppers and southern peas. He and his colleagues bred the nematode-resistant Carolina Wonder sweet pepper, Charleston Hot hot pepper, and many others, and he’s shared seedstock with us of southern peas releases that we’re hoping to be able to offer in the next few years.  He’s in the picture below at right, with colleague Floyd P. Maguire at left.

Across the street, Brian Ward gave us a fast tour of the organics section of Clemson’s Coastal Research and Education Center. Interesting projects included watermelon seedlings grafted onto gourd rootstock for greater disease resistance and vigor, a study of alternative pollinators for watermelons, rice trials, and seed increases for heirloom varieties of peanuts, southern peas, and corn. Alas, so much to see, but so little time!

Our final stop in the research portion of this trip was the Cherry Farm facility in Goldsboro, NC, for the Center for Environmental Farming Systems (CEFS), a collaboration between several NC ag departments. With 2,245 acres available, CEFS has a huge area to do all kinds of big studies, with long term studies of soil nutrition, tree alley crops, forest succession, animal husbandry, and many others. Research Operations Manager Andy Meier generously took time on a Sunday afternoon to show us around. CEFS helps provide the space and support for many NC ag folks and groups to do trials.  Their variety trials this year include wheat, barley, soybeans, and this southern peas trial with four repetitions. Again, so much to see, and so little time!

Next week we’ll spotlight two individuals who we visited who breed exciting new varieties.