Tag Archives: soil health

Getting a Soil Test

Soil tests are a simple and accurate way to learn more about your garden soil and determine what amendments it needs. A detailed soil test, a little research, and an understanding of the results can drastically improve your yields and eliminate recurring issues in your garden.

Where to Get Soil Tested?

There are a few ways you can get a soil test. While you may find simple home test kits at your local hardware store, these generally aren’t as accurate or detailed as a professional test. 

Typically, you can get your soil tested through your county extension agency or agricultural college. Many extension agencies and state colleges offer residents free or cheap soil testing. They typically include some recommendations if amendments are needed. Private labs also provide these services, but they may not be as affordable for home gardeners as the other options.

How to Find Your County Extension

To find your county extension agency try browsing the listings of Pick Your Own. They list contact information for county extension agencies across the United States.

When to Sample

We recommend having your garden soil tested every one to two years. Orchard areas typically only need to be tested every three years.

Late summer and fall are ideal times to collect soil samples. This time of year will represent how the soil’s nutrient status affects crops. If needed, you can take soil samples in spring, but you should avoid collecting frozen or waterlogged samples as they may not mix well.

Don’t collect soil after adding lime or other amendments. It’s best to wait several months or even longer if the weather is dry until they’ve dispersed into the soil.

Depending on the lab you’re working with, and how busy they are, it may take several weeks to get the results from your sample. It’s best to send them in well before you need the results.

Where to Sample

You want to get a good picture of the soil throughout your garden, not just in one spot. To do this, you’ll create a composite sample to send in, made from samples taken throughout the garden. For small-scale home gardens, five to eight samples are generally adequate. 

If your garden appears to have distinct slopes and soil types, be sure to get a sample from each area. Avoid taking samples from sites that don’t represent your garden well. These may include garden edges and unique wet spots.

How to Take a Soil Sample

Take soil samples using a spade or auger and collect them in a clean container. How deep you should sample depends on your garden type. Aim for small uniform cores or thin slices starting at the soil surface. 

For traditional backyard gardens, sample to the tillage depth. For no-till gardens, take one sample from the top 1 inch of soil and then take a second sample from the same spot at a depth of one to six inches.

For areas you’d like to establish an orchard, take a surface sample from zero to six inches deep and a subsoil sample from six to twelve inches deep. In established orchards, scrape aside plants and organic matter and take a surface sample. 

Once you’ve collected your samples, gently crush them and remove any stones and roots. Then allow your soil sample to air dry. Spread it out on a clean surface in a shady spot and make sure it dries before mailing. Don’t heat your soil to dry it.

Your samples should be at least one cup of soil in a plastic bag. Depending on the agency or lab, they may have you use or provide a specific bag. Follow your extension agency or lab’s instructions for sending your sample. Be sure to include all necessary paperwork and your name and address. 


The gardening science can sometimes feel intimidating, but it doesn’t have to! Getting your soil tested is a simple way to learn how to amend and improve your soil correctly. Your soil test and advice from the local extension agency can help you build healthy soil and grow healthier, more productive plants.

Soil Texture: The Jar Test

It’s easy to see that great gardens come from healthy soil. However, it’s less easy to understand how to build healthy soil. There are micro and macronutrients to consider, acidity, cover cropping, the soil food web, and so much more. One way we can examine our soil and easily make adjustments is by understanding its texture. Soil texture determines how it “acts,” like when you’re trying to dig a new bed or get heavy rain. 

One of the easiest ways to examine your soil texture is to do the jar test or the mason jar test. 

The Jar Test

To complete this test, you’ll need some basic supplies; a ruler, permanent marker, water, soil samples from the root zones of your plants, and a clear jar for each sample. You don’t need to go crazy with samples, but it’s worth doing a couple, especially if you have a large garden or multiple. 

  1. Place your soil sample in the jar. It should be about 1/3 of the way full. 
  2. Fill the jar almost to the top with water.
  3. Shake thoroughly for a couple of minutes. 
  4. Place the jar aside until everything settles. This may take several hours.

When you return to your jar, you’ll immediately notice that it has separated into layers. The bottom layer will be sand. Sand particles are larger and heavier, so they settle out first. The layer above the sand will be silt with slightly larger particles, and the top layer will be clay with very fine particles. You may also see some organic matter floating at the top.

Jar Test for Soil Texture DiagramNow you can begin measuring. If it’s helpful, mark the edges of the layers with your marker. Then measure the total height (not including water) and the height of each layer. Once you’ve got these measurements, you can calculate the percentage of each.

% Sand = (height of sand / total height) x 100

% Silt= (height of silt / total height) x 100

% Clay = (height of clay / total height) x 100

Now you can use this handy chart from the USDA to find your soil type based on the percentages. 

Soil Texture Chart from USDAFor example, if you got 60% clay, 20% silt, and 20% sand; you have clay soils.

Let’s say you got 15% clay, 15% silt, and 70% sand; you have sandy loam soils.

You can also use the NRCS Soil Texture Calculator.

What Does My Soil Texture Mean?

Different soil types behave differently.

Clay Soils

Soils higher in clay tend to be high in nutrients and hold water well. Unfortunately, they can also be hard to dig in, too dense for large roots to grow, and tend to become waterlogged.

Sandy Soils

Sandy soils are very easy to dig in and allow for easy growth of large roots (think big carrots). They also drain well and warm up quickly in the spring. Unfortunately, sandy soil doesn’t hold nutrients or water well, meaning plants grown in them may suffer from nutrient deficiencies and drought.

Silty Soils

Silty soils are in between sand and clay. They tend to have more nutrients than sandy soils and hold water better but are still easier to cultivate and dig than clay soil. Unfortunately, silty soils compact easily and tend to form a crust. They also have poor water filtration. 

How Do I Change My Soil Texture?

Most of us would love it if we got ‘loam’ as a result, but it’s unlikely we will. Our region and the land’s history will largely determine the soil we get to begin working with. 

The best amendment for any soil type is organic matter. You can add organic matter to your soil through composting, cover cropping, mulching, and manures. 

Be careful if you decide to add other amendments like sand or gypsum. These can make soil problems worse when added incorrectly. 

There’s a lot to learn about soil, but understanding soil texture is an excellent start to improving your garden. Use the jar test to learn about your soil texture today!

Fall Tasks: Mitigate Plant Diseases

Just like humans, plants are susceptible to a number of diseases. It’s an unfortunate part of gardening. Your cucumbers may suffer from Downey mildew, your tomatoes may get verticillium wilt, your potatoes may suffer from late blight, or your corn may get leaf rust. Thankfully, there are ways to strive for healthier plants. Here are some steps you can take this fall to help mitigate plant diseases. 

Study Plant Diseases

Try to identify the specific plant disease infecting your plants. Once you’ve identified a particular disease, you can find information about the transmission (how it infects your plants), different host plants, and what type of environment it requires to thrive. This information will help you control it. 

For example, you may have had a few tomatoes infected with Fusarium Wilt this year. Fusarium Wilt typically enters the plant through the roots, often in areas damaged by nematodes. Unlike many fungal diseases, it doesn’t spread by the wind. It’s typically brought in on infected soil or equipment. It thrives in acidic soil and will infect tomatoes, eggplants, peppers, pigweed, mallow, and crabgrass. Knowing this, you can take steps to mitigate the issue. Keep that bed free of these plants for a couple of years, amend your soil with lime, and sanitize all equipment. 

Clear Away Diseased Plant Material

Many of us strive to have natural systems in our gardens, and what seems more natural than just letting plant material decompose right in the bed? While this is sometimes fine, if the material is diseased or your garden is prone to diseases of that crop, you should remove the plants. 

Diseased plant material can be burned, buried away from the garden, or composted in a well-managed compost pile. Compost piles must reach a temperature of at least 140 degrees F to kill fungal diseases!

Sow Cover Crops

Tillage radishes are an excellent choice for fall and winter kill in areas where temperatures reach below 20°F. They also have biofumigant properties, ideal for suppressing diseases and pests. They also improve soil structure, creating spaces that allow air and water to enter and a great for breaking up hard pans.  

Other fall cover crops like Austrian winter peas and winter rye are also great for building healthy soil by adding nitrogen, nutrients, and organic matter. 

Write Down Where You Planted Crops

Fall tomatoes (mitigate plant diseases)Crop rotation is key to disease prevention in every garden. No matter what size your garden is, come next spring, it can be tough to remember exactly where you planted what the previous season. While many don’t have the time or desire to create a comprehensive garden journal, you should at least sketch out your 2022 crop layout before you forget it this fall. That way, there’ll be no doubt in your mind next spring that you’re planting your tomatoes in a bed that didn’t previously have nightshades. 

Alternatively, there are many gardening planners and apps available. Check out the Southern Exposure Garden Planner to quickly create layouts for your records and plan for next season. 

Start Building Healthy Soil

It’s a good idea to have your soil tested in the fall and work to improve it over the fall and winter. Begin a compost pile and add compost to your garden. Compost adds nutrients and helps improve the soil structure leading to healthy root systems. Plants are far less susceptible to disease when grown in healthy, well-balanced soil. 

Research Disease Resistant Varieties

Even among open-pollinated varieties, there are many disease-resistant cultivars available. They’re worth looking into if you struggle with a specific disease each year. 

On the Southern Exposure website and catalogs, you’ll find some crops like tomatoes and cucumbers are marked with acronyms in brackets after their name. These acronyms stand for known disease or pest tolerance and are listed in our keys to disease and pest tolerance. For example, a variety marked with “an” has resistance to Anthracnose.  

Many other seed companies use the same system, though the acronyms may vary slightly. You can also find lists of disease-resistant varieties through your local extension agency or a quick internet search.

Sanitize Your Equipment

Especially when dealing with a highly infectious disease or pruning and handling diseased plants, be sure to sanitize equipment. Sanitize small tools like pruning shears, garden knives, and trowels with alcohol. You can also use a bleach solution to wash larger tools and work surfaces. 

While having a perfect garden is impossible, we can strive to minimize and even mitigate plant diseases. Taking these steps this fall will help you create a healthy garden and have a more productive 2023!