Tag Archives: organic

Improving Heavy Clay Soils

Gardeners rarely begin their journey with a plot of perfect soil, but it’s something we all dream about. In the Southeast, many gardeners have to work with heavy clay soils. While clay soil is rich in minerals and many nutrients, it’s prone to compaction, doesn’t drain well in wet weather, and doesn’t hold water well during droughts. Growing certain root crops like large carrot varieties can be especially tough.

Clay soils are a great foundation to improve on. Here are a few organic methods to improve your heavy clay soil. 

Practice No-Till (or minimal-till) Agriculture

It may sound counterintuitive, but tilling can make clay soils worse. Tilling increases soil compaction and kills beneficial fungi and micro-organisms. 

Cover Crops

Cover crops add nutrients and organic matter to the soil. Great choices for improving clay soils include buckwheat, clover, and wheat. Clover has the benefit of being a nitrogen-fixing legume, meaning that through a symbiotic relationship with bacteria, it captures nitrogen from the air and adds it to the soil.

You may also want to mix in large or deep-rooted cover crops like daikon radishes, lava beans, and alfalfa. These crops help break up compacted soil and create channels for air and water as their roots decompose.

Chop & Drop

You can also use a method commonly used by permaculturalists called “chop and drop.” This method involves growing crops like comfrey, pigeon peas, moringa, sun hemp, and sorghum. These crops are chopped and dropped on the soil to decompose. Comfrey is a popular choice for this in perennial gardens and fruit tree guilds.

Broadfork

Broadforking your soil is a great way to loosen soil without disturbing the layers or structure. It helps mitigate compaction and preserve beneficial organisms and fungi in the soil. 

Create Permanent Beds

Even just walking on your garden soil can cause severe compaction. Creating permanent beds that you don’t till, step on, or use machinery will help make light, fluffy soil. 

Use Terraces or Swales

If your property has heavy clay soil and a slope, you’ll probably deal with water issues. Planting in rows or terraces that are perpendicular to the slope of the land will help slow down the water in your garden and reduce erosion issues. Swales built on contours take this further and are a great way to catch large amounts of rainwater, allowing your plants to access it slowly, even on significant slopes. 

Spread Compost

Finished compost is the quickest way to beef up the organic matter in your soil. Adding a couple of inches of compost to each bed adds nutrients, improves water retention and drainage, and lightens the soil.

Use Mulch

Mulch helps block weeds, hold moisture, and keep soil temperatures cool. It also adds a lot of organic matter to your soil as it decomposes. Any organic mulch can help improve your clay soils, including straw, leaves, grass clippings, woodchips, and hay. Keep in mind that hay tends to have a lot of weed seeds.

Grow Varieties Adapted to Heavy Clay Soils

Improving clay soils isn’t something that happens overnight, especially in large gardens. If you’re planting in a garden with heavy clay soils this year, try some varieties that are adapted to these conditions.

  • Chantey Red Core Carrots
    This blocky, broad-shouldered variety with a blunt tip is well-suited to growing in clay. It was introduced from France in the 1800s.
  • Danvers 126 Carrots
    These carrots taper to a blunt point and are especially suited to growing in clay soil. The strong tops aid harvesting.
  • Everona Large Green Tomatillo
    These plants produce large, tasty tomatillos and thrive even in heavy clay soil and drought.  Seed collected by Barbara Rosholdt from tomatillos planted by Mexican workers at the Everona sheep dairy near Unionville, VA. Introduced in 2008 by SESE.
  • McCormack’s Blue Dent
    This beautiful dent corn makes delicious light blue flour and is especially suited to the eastern U.S., clay soils, and drought-prone areas. Introduced in 1994 by SESE. Bred by Dr. Jeff McCormack from a cross between Hickory King and an unnamed heirloom blue dent.
  • Oxheart Carrots
    A good carrot choice for shallow or heavy clay soils that most carrots don’t like. Dating to 1884, this variety produces thick, sweet “oxheart”-shaped carrots, 5-6 in. long and 3-4 in. wide, weighing up to a pound!
  • Pike Muskmelon
    Bred specially for growing in unirrigated clay soil, this vigorous melon has outstanding flavor and good disease-resistant. Introduced in 1935, Aaron Pike of Pike & Young Seeds; seedstock supplied to SESE by Aaron Pike’s niece.
  • Tennessee Red Valencia Peanuts
    This pre-1930 produces rich, sweet peanuts with red skins. It’s easy to grow without hilling, even in clay soils.
  • Texas Gourdseed Corn
    Originally brought to south Texas by German farmers who migrated from Appalachia during the late 19th century, this variety withstands drought and does well in clay soil. In south Texas, this is considered to be the best choice for tortilla flour.
  • Turga Parsnip
    This Hungarian heirloom produces short, stout roots that are good for heavy clay soils.
  • Southern Peas (Cowpeas)
    These productive peas are well-adapted to poor soils and drought. We carry 16 varieties at SESE.

11 Free Organic Methods to Add Nutrients to Your Garden

For many, gardening is not only an enjoyable activity but a great way to save some money. Unfortunately if you weren’t raised on a farm or with a large garden it can be difficult to have a successful garden withtout spending loads of money on fertilizer and soil amendments at the garden supply store. Thankfully it is possible to maintain a healthy garden without spending a dime! Try a combination of these methods to increase your soil’s nutrients and reap a better harvest.

Leaf Litter

Leaf litter is great because it can be used to make compost or can be applied straight to the garden as mulch. As a mulch it provides habitat for beneficial insects, blocks weeds, holds in moisture, and slowly breaks down adding nutrients to the soil.

Leaves can be gathered from your yard or woodlands. You may find piles that have collected behind fallen logs or stones after being carried by the wind. In gathering leaves remember to leave some for the natural ecosystem. It’s tempting but don’t strip any area of all it’s leaf litter. Even if you don’t own wooded property you can probably still find free leaves. Many cities and suburbs collect them and you can get bags of them for free, just ask around.

Grass Clippings

If you mow your lawn at all grass cllippings are deifintely worth getting a bagger for. They make great mulch to block out weeds, hold in moisture, and provide a lot of nitrogen. Grass clippings can also be soaked in water to create grass clipping tea. Watering plants with grass clipping tea provides a fast acting nitrogen boost.

Like with leaf litter, some areas may bag their grass clippings for collection and can be picked up for free.

Compost

Compost is surprisingly easy to make right in your backyard. The most important thing to remember when making compost is to have a mix of of “green”  or high in nitrogen material and “brown” or high in carbon material. Examples of “green” material include grass clippings, vegetable scraps, and weeds. “Brown” material includes leaf litter, wood chips, straw, etc. The compost should be turned occasionally and watered to keep it moist as needed.

Compost can also be used to make compost tea the same way grass clipping tea is made. Many people choose to add powdered egg shells to compost tea for an extra boost of calcium.

Some cities and towns now offer free compost made from local plant waste like grass clippings and leaves. If you go this route you may want to have it tested for herbicides.

For more on making compost read, How to Make Compost from Mother Earth News.

Straw

Straw is a choice mulch but can be rather pricey to purchase. Look for bales leftover from Halloween decorations or consider growing a patch of wheat for a double duty crop!

Wood Chips

Wood chips can be used as mulch or can be added to compost piles. Both in compost and as a mulch they offer similar benefits to that of leaf litter but break down more slowly.

Other Plant Material

Any plant material that doesn’t contain weed seeds can be used as fertilizer. Examples include wheat chaff, weeds, corn stalks, etc. These can be applied directly to the garden or composted. Green plant material like freshly pulled weeds can be used in place of grass clipping in grass clipping tea.

Cover Crops 

Cover croping may sound like something for a big farm but it’s actually very easy and effective to implement in a backyard garden. Some cover crops like vetch or clover are legumes and add nitrogen to the soil as they grow. Others like buckwheat add nutrients as they die and rot or are tilled under. Many cover crops come with added benefits like attracting pollinators.

Check out this post by Ira Wallace for more on Cover Crops.

Urine 

It sounds wierd but urine is actually a great fertilizer if you’re not too squeamish. It can be collected and saved up then diluted (10 parts water to one part urine) and used to water plants for a nitrogen boost. Most people or more comfortable using this on fruit trees and shrubs than their annual vegetable crops.

Wood Ashes

If you have a wood stove or backyard campfires wood ashes make a great free garden amendment, addding potassium to the soil. They should be used in moderate amounts as they also act as a liming agent. They raise the soil’s pH making it less acidic. If this is helpful for your soil conditions it’s worth noting that they’re only about 1/3 as effective as commercial lime so you may need a larger amount.

Hugelkultur Beds

If you’re okay with a more involved project you may want to try building a hugelkultur bed for longtime fertility. Hugelkultur beds involve a pile of woody material which breaks down over time providing a long lasting nutrient source.

You can learn more about the benefits of hugelkultur and how to make a hugelkultur bed here

Manure

Manure can come from your own livestock or you may find it free from a local farm. Try checking with places that board horses as they typically don’t use it the way many farms do. If you’re sourcing it from anywhere besides your backyard be sure that the animals haven’t been fed plant material that was grown using herbicides as these can still be in the manure and will kill your garden.

It’s also worth noting that excessive use of manure can cause a phosphorus build-up which pollutes local water sources and can tie up other soil nutrients. This problem doesn’t occur with any plant based fertilizers so manure should be used sparingly.

If you’re unsure of where to start consider having your soil tested. Your local agriculture extension agency will be able to identify what your soil needs and advise you where to begin. Growing good, organic food shouldn’t be expensive. Experimenting with these tried and true methods can help you keep a frugal yet productive garden.

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.