Whether you’re an avid gardener or just starting out, learn all the basics of how to care for soil in vegetable gardens. Learn how to tell what type of soil you have, how to amend it, and even how to make your own perfect soil.
Featured Expert:
Larry Sagers, Utah State University extension horticulture specialist, and radio host and newspaper columnist. Contact Larry at lsagers@ext.usu.edu
Featured Expert:
Adrian Hinton is a Utah State University Extension Agent. Utah County residents can contact him at adrianh@ext.usu.edu.
If you live outside Utah County contact your local extension agent.
Special Guest:
Danelle Bates, a new homeowner planning her garden.
Click on a topic below to view additional information.
Soil Types
There are three types of soil: silt, clay and sand.
To help you determine your soil type, do a simple test by rubbing a bit of dry or moist soil between your fingers and noting its characteristics.
Sand is made up of very coarse particles, and feels rough when rolled between your fingers.
Clay is smooth, nonporous and sticks together in clumps, when it is dry it feels smooth but when it is wet it feels sticky.
Silt is made up of very fine particles, it feels smooth and powdery, when wet it feels smooth but not sticky.
Check out this site to see characteristics of different types of soil.
Air in soil is vital because the roots of plants need it. The plant breathes through the roots the same way it does through the rest of its structure.
Raised beds help to maintain air in the soil, because when we work in the garden we walk on the ground and compact it.
Tips on Soil Types from Larry Sagers
Sand, clay, and silt particles make up the mineral portion of soil. This is the solid part of the soil and should make up about 45% of the total soil.
To test soil texture, moisten soil and try to roll a ball with your fingers: clay soil will form a smooth sticky ball, sandy soil is somewhat grainy and will not stick together.
If you have relatively equal amounts of the three components in your soil, it is called a loam soil.
They all work together to form and ideal soil. The sand drains well, the clay holds the water and minerals well, and the silt is intermediate between the other two.
In most areas of the world the soil contains either too much sand or too much clay. So we have to learn to work with the soil that we have.
If you have a problem soil don’t learn to live with it, learn to improve it.
The ideal soil is 45% mineral fractions (sand, silt, clay), 5% organic material, 25% air, and 25% water.
We need to pay more attention to the air portion of the soil. That is how the plant roots get oxygen. So don’t work soil when it is wet.
There also needs to be good aeration of the soil. Always try to keep it nice and loose and fluffy.
Don’t mix sand and clay because then you will get low grade concrete.
Don’t compact your soil or till it when it is wet.
Organic Material
Soil needs about 5% organic material.
The presence of decomposing organic matter in soils has long been recognized as a nutrient source for plants and useful in maintaining and improving structure in clay soils and in improving the water-holding capacity of sandy soils.
This article contains information about applying organic material to your garden with out composting it.
Organic matter is anything that was once living. So there are lots of different kinds of organic matter.
Add organic matter to your soil. If you have clay soil you will want to add something courser that holds the water less than peat moss.
Each year add a minimum of 2 inches of organic matter to your garden soil.
The rule of thumb is to apply 1- 2 inches of organic matter to the surface of the soil before tilling.
If applying manure get something that has been hot composted or treated so the weed seeds will not be viable.
Do not use dog or cat manure in your gardens. These animals can carry parasites that you would not want in your garden.
Do not use fresh manure because it is normally very high in ammonia.
Use manure that is at least one year old.
For more effective heating build a heap that is at least 4X4X4 feet.
Organic mulching protects and improves soil.
Composting
Composting can convert food and garden waste into dark colored soil (humus) in a matter of a few weeks.
Compost is decomposed organic material. Compost is made with material such as leaves, shredded twigs, and kitchen scraps from plants.
Why Compost
Compost is one of nature's best mulches and soil amendments, and you can use it instead of commercial fertilizers. Best of all, compost is cheap.
Ingredients
Compost is one of nature's best mulches and soil amendments, and you can use it instead of commercial fertilizers. Best of all, compost is cheap. This site contains a table of ingredients to use and the nutrients they add to the compost.
For effective compost you need a good mix of materials both green and brown.
This list describes some of the items you may want to add to your home compost pile.
There are some things that shouldn't be put into compost piles.
Providing adequate sources of carbon and nitrogen is important since these elements are required by microorganisms for growth and cell division. Carbon also serves as an energy source for soil organisms. See this list of items to add and those to exclude.
Techniques
Composting is easy. You don't need any special knowledge or equipment, and it takes only a little extra effort to collect your wastes and establish an active compost pile. Vermicomposting uses earthworms to turn organic wastes into very high quality compost.
It's easy to make good compost. Good compost reduces almost every other kind of gardening problem.
Here are some tips to creating wonderful compost, without taking up too much space in your yard.
Compost is one of nature's best mulches and soil amendments, and you can use it instead of commercial fertilizers. Best of all, compost is cheap. This site has complete instructions on how to compost.
Compost is considered "black gold" because of its many benefits in the garden.
When your compost is finished you will have dark brown, rich, material that will be perfect for the garden.
This how-to document contains information about composting fundamentals for those interested in an introduction to how composting should be done.
Advantages
There are a number of benefits from adding compost to gardens and lawns.
Landscape waste accounts for up to 20% of the waste being put in landfills. Composting helps alleviate the burden of all this waste in our landfills.
Tips on Composting from Larry Sagers
You need at least 5 bushels of materials to begin a compost pile.
Composting is an excellent way to recycle nutrients back into the soil and also to improve your soil.
There is nothing better for your soil than adding organic matter.
Grass clippings are high in nutrients but very low in solid matter. So you get very little, long lasting, composted material from grass clippings.
Use the grass clippings to add nitrogen and then add other materials that contain carbon, such as leaves.
Leaves are an ideal source to add to a compost pile.
Composting materials have to have three things: be abundant, be cheap, and weed free.
Some things you need for your compost pile to work effectively are: oxygen (thus the need to dig up or tumble weekly), water (compost should feel like a sponge that has been wet down and then wrung out), you may need to add a little nitrogen fertilizer if you have lots of brown, or carbon materials in your compost.
You will need equal amounts of brown materials (dry leaves, sawdust, wood chips) and green matter (grass, trimming off of salads and vegetables, animal manure).
Do not put in meat scraps or eggshells. These will attract animals such as mice, raccoons, and skunks.
Mulch
Mulching is one of the simplest and most beneficial practices you can use in the garden. Mulch is simply a protective layer of a material that is spread on top of the soil.
Mulch is any substance spread on the ground to protect plant roots from heat, cold or drought or to keep fruit clean. Mulching your garden shows you really care about your plants.
Mulching helps to prevent evaporation.
Mulch is spread on the ground to protect plant roots from heat, cold or drought or to keep fruit clean.
Mulch, by definition, is a layer of bark, sphagnum peat moss, muck peat, compost, pine needles, gravel, plastic, or any similar material uniformly spread on the surface of the soil under plants.
Mulching is a long-time practice of gardeners to prevent loss of moisture and to control weeds.
By spreading an inch or two of mulch between the rows of your vegetables, you can slow down or in some cases prevent re-growth of weeds. Mulching also helps to conserve water, because it reduces evaporation of moisture from the soil. In addition, mulch will absorb water from sprinkling or rain showers and the mulch helps check soil erosion.
For answers to frequently asked questions about mulching see this site.
See this site for factors you should consider when selecting mulching materials.
You should be matching the mulch to the crop, weather conditions and soil.
Organic mulch needs to be applied to a depth of 2-3”.
Grass clippings do not make good mulch because they prevent air getting through to the plant and cause the water to run off.
Organic mulches add nutrients and humus to the soil as they decompose.
Plastic mulch
Some examples of inorganic mulches are black, clear, or red plastic and newspaper.
Clear plastic is warmer in temperature for the plant but it does allow weeds to grow.
Black plastic is cooler for the plant. Weeds cannot grow under it and it conserves moisture.
Some of the advantages and disadvantages of using plastic mulches are outlined in this site.
Using Mulch
This site includes a table that shows different types of mulches and how to use them.
Fertilizing
Soil needs three main things, Nitrogen, Potassium, and Phosphorus. The numbers on the bags of fertilizer tell us what proportion of each is in the mix.
A local garden store or extension service will be able to advise you which fertilizer is best for your area.
The amount of fertilizer to apply depends on the natural fertility of the soil, amount of organic matter, type of fertilizer, and the vegetables being grown.
Vegetable plants, like all other green plants, require several nutrient elements for growth, development and productivity.
This site will provide information to help ensure that your plants receive ample amounts of nutrients. It addresses factors involved in plant growth, types of fertilizer, and how much fertilizer to apply.
Application
You can get full value from the fertilizer you use, if you will follow a few basic procedures concerning application.
For help to understand soil test results, and how to apply fertilizer see this site.
How Much Fertilizer
A good figure to use for fertilizer on a vegetable garden is 1 lb Nitrogen per 1000 sq ft.
Think of fertilizer like salt. If you over fertilize you can possibly harm the crops.
Plants need 16 essential nutrients, or elements. This site tells what they are and the roll they play in plant growth.
Learn how to get the most out of the fertilizers you use, and how to use them properly from this site.
Micro Nutrients
Micro nutrients are other elements that plants need like Iron, Boron, copper, zinc, etc. On this site you can access information about each of these micro nutrients.
There are 11 micronutrients that are needed in tiny amounts. This site talks about these as well as all fertilizing needs.
Tips on Fertilizer from Larry Sagers
It is always a good idea to get your soil tested to establish a base line before adding fertilizer.
Various soil types and different vegetables diverse fertilizer needs.
Fertilizer bags have three numbers on them the first represents how many parts nitrogen, the second is how many parts phosphorus, the third is how many parts potassium. If there is some in each number it mean it is a complete fertilizer.
Incomplete fertilizer is useful when providing crops with supplemental feeding after planting.
If you want to promote a lot of green growth such as lettuce or grass you will want a fertilizer that is higher in nitrogen.
For tomatoes you will want a fertilizer that is higher in phosphorus or the second number.
Soil Testing
There are soil test labs at most universities.
If you live in an agricultural area, there are usually commercial labs nearby.
Most University Extension Services have testing labs. They are in virtually every county in the United States. This site from Mississippi State University answers questions about soil samples.
When gardeners guess about the need for lime or fertilizers, too little or too much is likely to be applied. This site includes instructions on how to take a soil sample.
You should know what type of soil you have. This is determined by a soil test. It is recommended that you take a soil test of your garden.
A soil test will measure the amount of clay, sand, and organic matter in your soil and will also test the ph.
Contact your local extension service to find out how to take a soil sample and where to get it tested.
Tips on Soil Testing from Larry Sagers
Take your soil sample to a commercial or university-testing lab. Most of the home tests are not very accurate. You need to have accurate information about your soil.
A soil test will cost about as much as a shrub. So before putting in lots of plants spend the money and get your soil tested. It is cheap insurance. Then you will know what will grow in your area and what will not.
The key to having a more productive garden is to know what you need to put on to make them better.
Knowing what you need allows you to add fertilizer only as you need it.
Steps for getting soil tested
Obtain the mailing package from the local Extension Service.
Collect soil sample.
Fill out the form, include payment and mail the sample to the lab.
To obtain further counsel on the soil report, visit the Extension Service.
