Gardeners are an observant bunch. We watch for signs of water stress, damage from insects, or fungal infestations. Our eyes scrutinize new leaves for healthy color and texture. But sometimes we forget to examine the part no garden can be without – the earth beneath our feet.
What’s the big deal? Well, knowing what type of soil you have and what nutrients (plant food in its elemental form) it contains will make you a smarter gardener AND help you to save money by not buying extra fertilizers your soil doesn’t need. To do this you will need to know about two things – soil structure and nutrient levels. Let’s dig in.
The Ingredients in Soil
Soil scientists tell us that all soil is made from a combination of clay, silt, and sand. Add in organic material (leaves, compost, twigs, bacteria) and you’ve got that stuff in your garden beds. What makes the difference from one spot to another is the ratio of clay to silt to sand. How can you tell where your garden lands?
The simplest way to tell is pick up a handful and squeeze. If the moment your hand comes out of the ground, sand starts pouring down, you probably have a sandy soil. Now squeeze the dirt and open your hand. If the soil stays together so you can see the outline of your fingers, you have a high amount of clay elements. But if the soil stays mostly together (see image above) but crumbles around the edges you’re in luck! You have an even mixture of soil ingredients and your soil is probably healthy.
What if your soil lands somewhere out on the soil triangle edges? It probably means your garden will benefit from soil amendments. In most cases the best and safest thing to add is composted organic material. This helps to break apart clay soil, beef up silty soil, and help sandy soil hold water and other nutrients. Of course there are a lot of other soil amendments available for sale. You can read the packaging and make a guess about what amendment will help or you can do the smart thing and have your soil tested to know what it needs. Here’s how.
Measuring a Soil’s Nutritive Values
Soil testing begins by gathering a representative sample of your garden soil. Dig about six inches down into the ground in several spots in your garden and collect a handful of soil in each location. Avoid collecting the top inch of soil as it will not be representative of the soil the roots are most in contact with.
After you have gathered about two cups of garden soil, spread out the soil and allow it to air-dry. Remove any large rocks or wood chips before placing your sample in a sturdy plastic bag – a zip-locking freezer bag works very well. Label the bag with your name and the location where the samples were taken (e.g. Front Garden, West Slope). This can then be sent to your state’s testing lab or other quality testing lab along with a soil sample request form and payment. Here’s a quick list of who to contact for this:
- Texas AgriLife Soil Testing
- New Mexico Soil Testing Labs
- Arizona Soil Testing Labs
- Click Here for all other states
Once you receive the results of this soil testing you will have a better understanding of what your soil may need for improved fertility. Now you will be able to make better choices when buying soil amendments and save money in the process.
If you enjoy herbs and organic gardening, you’ll want to meet Ann McCormick, the Herb ‘n Cowgirl. A life-long gardener, she has devoted her time for the last 20 years to writing and speaking about her favorite subject. Ann is a feature writer for The Dallas Morning News.The Herb ‘n Cowgirl also shares her love of herbs and her gardening techniques as a speaker and media guest. She lives in Fort Worth, TX with her husband of 35 years and an assortment of dogs. To find out more about the Herb ‘n Cowgirl visit her at www.herbncowgirl.com.