Tag Archives: soil building

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.

Using Manure in the Garden

It’s now believed that farmers have been using manure to fertilize their crops for at least 8000 years! Spreading manure on fields and gardens to increase soil fertility has long been common, especially when most folks were keeping livestock. Today, it can be more tricky. So whether you’ve got your own backyard farm or not, here are a few things you should know about using manure in the garden. 

Pros

  • It’s full of nutrients! Manure is an excellent source of primary plant nutrients nitrogen, potassium, and phosphorus. It also includes secondary nutrients; calcium, magnesium, and sulfur that may not be found in commercial garden fertilizers.
  • Manure adds organic matter and improves soil structure. This allows optimum root growth and increases the soil’s ability to hold moisture.
  • You can often find manure for free or use your own from your own livestock.

Cons

  • Fresh manure can contain bacteria that can contaminate crops and make you sick.
  • It often contains weed seeds.
  • It may contain pesticides, herbicides, or other chemicals.
  • Fresh manure contains high levels of nitrogen, ammonia, and salts which can burn crops. 

Sourcing Good Manure

If you own livestock, using their manure is the best choice. To fertilize your garden, you can use chicken, goat, cow, horse, rabbit, and other livestock manure. Avoid cat and dog waste as their feces can contain toxins and heavy metals that will remain in your garden. 

If you don’t own animals, it may be possible to source manure from a local farm. However, you may want to ask some questions. Herbicides can stay in manure and ruin your garden, so it’s essential to ask if the animals were allowed to graze where an herbicide was sprayed. 

It’s also worth noting that not all animal manures are the same. Manure from herbivores like horses and cows has a lower nitrogen to carbon ratio than omnivore manure like that from pigs and chickens. Therefore herbivore manure won’t burn your crops even if it’s fresh. You should also note that horses don’t digest seeds, so horse manure will have more weed seeds in it. 

Composting Manure

Some of the “cons” of manure are easily taken care of by composting it. Composting your manure will kill any bacteria and allow it to mellow, so it’s not high in nitrogen, ammonia, or salts and won’t burn your crops. A good, hot compost pile can also render weed seed inviable. 

To compost manure, you’ll want to follow the same techniques we discussed in Black Gold: Making Compost. Mix your nitrogen-rich manure with good sources of carbon such as old leaves, straw, or shredded paper; alternate layers as you build your pile. Keep the pile moist and turn it over every few weeks to encourage aerobic decomposition. It’s ready when it looks like black, crumbly soil and is no longer hot or smelly. 

You can apply composted manure to the garden the same way you use your regular compost. Spread a few inches on a bed before planting, add it to homemade potting mixes, or side-dress crops. 

Aging Manure

Your other option is to age manure rather than compost it. It’s exactly like what it sounds. You pile it and leave it. This process can take longer than composting, particularly if you’re starting with manure that’s high in nitrogen, like pig manure. 

Applying Fresh Manure

If you want to apply fresh manure, you need to select “cool” manure like horse, cow, or rabbit manure. Other manures, including goat, poultry, and pig, may burn your crops. Goat and sheep manure may be okay if it’s mixed in with carbon-rich bedding like straw or hay.

One of the safest ways to use fresh manure is to follow the USDA National Organic Program Guidelines. They state that if the crop may come into contact with the soil, whether it’s touching them directly like with beets or splashing on them like with Swiss chard or cucumbers, it must be applied 120 prior to harvest. If the crop won’t be in contact with the soil like corn or dry beans, the manure must be applied 90 days prior to harvest. 

It’s a long time! This timeframe keeps crops safe from bacterial contamination such as E. coli and Salmonella. However, many home gardens don’t feel the need to follow such stringent guidelines. Just make sure you wash your veggies well if there’s a chance they’ve come into contact with the manure, especially if you don’t know where the manure came from.

Can You Use “Humanure?”

Using composted human waste to fertilize crops used to be common throughout much of the world. Composting human waste can reduce pollution and water consumption. Setting up a composting toilet is also much easier and cost-effective than installing a septic system and is a popular choice for off-grid and tiny homes. 

So is it safe? Yes, when done correctly. There are a number of fairly basic considerations to composting human waste. For example, you want to ensure your compost bins aren’t on wet ground or somewhere they could contaminate ground or surface water. You should also compost your waste for a year before use, and you should use it around fruit trees, berry bushes, and ornamental plants where it won’t get on food crops. Modern Farmer has a more detailed piece on humanure you can find here.

 

10 Easy Ways to Improve Your Soil

Want healthy plants? Start by building healthy soil. Your soil health can affect your plant’s productivity, disease and pest resistance, and more. Use these ten strategies to improve your soil and build a healthier, more productive garden.

1. Start composting.

Compost enriches the soil and adds structure and beneficial fungi and bacteria. It’s an excellent amendment for any garden and easy to make yourself. Check out our post, Black Gold: Making Compost, for easy directions to get started in your backyard.

Those without yards can consider vermicomposting or check with community gardens or city compost facilities to bring kitchen scraps to and access aged compost.

2. Grow cover crops.

Cover crops are not just for big farms! Cover crops help improve the soil in many ways. Some are “nitrogen fixers” like clover and vetch and add nitrogen to the soil as they grow; other crops like buckwheat help quickly build up organic matter and make excellent mulch.

All cover crops are a good way to cover the soil. They shade it holding in moisture, provide habitat for beneficial insects and pollinators, and their roots hold the soil preventing erosion.

You can read more about using cover crops in your garden here.

3. Get a soil test.

Testing your soil can help you make the best choices for your garden, saving you time and money. You’ll learn what nutrients may be missing and whether you should amend your soil’s pH. Check out Understanding Soil Tests for a more in-depth explanation.

You can purchase at-home soil tests at most garden centers or send your soil to be tested. Many universities and state and county extension services offer very affordable soil testing.

4. Understand the soil food web.

The soil food web is similar to a “food chain” but is non-linear. It’s made up of plants, animals, and all the organisms in the soil from visible insects and fungus to microscopic bacteria. A healthy soil food web is key to a healthy garden and ecosystem. Learn more by reading our post, The Soil Food Web.

5. Reduce erosion.

Not everyone is blessed with a large, perfectly flat garden site. Even if you are, wind can still wreak havoc on exposed soil. Don’t lose soil to the effects of wind and water.

If you live in a windy area, utilize windbreaks. These can be fencing, shrubs, or trees. Even young shrubs and trees can make a surprising difference.

To prevent water erosion, you should try to keep your soil covered. Use cover crops whenever possible and keep the soil around plants mulched. Permanent pathways with a cover crop like clover are ideal.

If your property is sloped, look into permaculture methods like planting on contour and building swales. These can help you stop erosion and collect water for your plants!

6. Provide habitat for beneficial insects.

When people hear beneficial insects, they often think of bees, butterflies, and other pollinators. While you should strive to help these species, there are many more that also play key roles in keeping your garden healthy. These include many predatory species such as wasps, beetles, and mantises.

You can support beneficial insects in many ways. Using cover crops and mulch, as I mentioned above, helps provide habitat as does planting native species and leaving dead material in your garden (unless it has a pest or disease issue). You can also create your own habitat by building an insect hotel.  Of course, it’s also important to avoid using pesticides. Even organic pesticides can spell doom for beneficial insects as they usually affect more than one species. 

7. Use mulch.

I’ve mentioned mulch a couple of times now, but it’s incredibly helpful in the garden. It helps to block weeds, keep the soil cool and moist (or warm in the winter), and provides structure and organic matter as it breaks down.

Check our post, Mulch Ado…, to learn more about why mulch is important and how we use it at SESE.

8. Rotate your crops.

Whether you have an acre in garden or just a tiny little plot, you should rotate your crops. Rotating crops prevents pests and diseases from building up the soil where you grow a particular plant. It also helps to reduce nutrient depletion. One year you grow heavy feeders like tomatoes or corn, and the next, you grow nitrogen fixers like beans and peas or a cover crop.

Need advice? See Planning Crop Rotation by Plant Family.

9. Amend your soil.

As you’ll learn from your soil test, it is sometimes necessary to add amendments to your soil. These amendments can be used to change the soil’s pH like lime, wood ash, or peat moss. Other amendments allow you to add the macro and micronutrients that are necessary for plant growth. These include manure, compost, eggshells, greensand, and fertilizer.

Learn more about amendments and common nutrient deficiencies in plants here.

10. Reduce or eliminate tilling.

Rototilling may seem like a crucial part of gardening, but many farmers, gardeners, and scientists have discovered that it’s possible to grow a more productive and more environmentally friendly garden by ditching the tiller.

Going no-till reduces compaction and keeps the soil structure intact. It allows you to use plant and cover crop residue as mulch that will decompose as it would in a natural ecosystem. It also allows beneficial bacteria, insects, and fungi to thrive in the soil. 

Follow these tips to build healthy soil in your garden.