Mother Nature provides plenty to grow healthy lawns, gardens and landscapes. But as many homeowners know, some lawns sometimes need a little extra boost to complement nature. Soil sometimes must be amended so plants can thrive. Only after the right composition is created can plants take root and perform to the best of their abilities.
The Colorado State University Extension defines a soil amendment as any material added to soil to improve its physical properties. The goal is to provide a better environment for roots. Depending on what you are starting with, any number of ingredients must be added to the soil recipe. Water retention, permeability, drainage, aeration, nutrients, and water infiltration are some of the things amendments can improve when added to soil.
Before homeowners add anything to the soil in their yards, it is first important to determine what that soil needs. Homeowners may notice if soil is overly sandy or full of clay, but further testing can confirm what the soil is lacking. Soil tests are often available through local cooperative extension offices or private laboratories. Speak with a nursery or garden center about where you can get your soil tested. A comprehensive test may cost between $5 and $10 and can provide invaluable information that saves you hundreds of dollars in wasted plants and materials, not to mention effort. Some labs also can tailor their recommendations based on the type of planting you will be doing. For example, a vegetable garden may need different amendments than a row of azalea bushes.
Organic matter is a preferred soil amendment used by professional and novice gardeners alike. The decaying remains of plants release nutrients that are absorbed into the soil and used by microorganisms and bacteria, creating a healthy environment for plants. Organic material may break up compacted soil to increase drainage. In sandy soil, organic material serves as a sponge to keep water from washing away. Compost and manure are two examples of frequently used organic materials. Both of these materials are readily available at little cost.
Compost can be produced at home from food and plant scraps. Raked leaves and small amounts of grass clippings can be added to compost. Over time, the decomposition process will turn scraps into a nutrient-rich, dark brown substance that provides many plants with all they need to thrive. Compost is particularly useful in vegetable gardens.
Manure should come from herbivores, or those animals that sustain themselves on grass and other plants. Carnivores can produce harmful bacteria in their waste, which is not safe to use in gardens, particularly food-bearing gardens. Manure can be commercially purchased, or avid gardeners can work out arrangements with nearby livestock owners and farms. These people may be more than willing to give you manure for little to no cost if you cart it away. Dried manure is preferred because it will have minimal odor.
Additional forms of organic amendments include wood ash, sphagnum peat, wood chips, sawdust, and worm droppings.
Inorganic amendments also may be used, and are usually relied on to improve water retention and drainage. Vermiculite, perlite, pea gravel, and sand are examples of inorganic amendments. A combination of organic and inorganic amendments can create the perfect mix for your needs.
Soil amendments typically are added to new and unplanted beds. Peat moss and shredded bark take years to decompose and will serve as long-term amendments in the soil. Compost breaks down quickly and may need to be worked in more frequently.
Experts recommend spreading amendments on the planting bed and then using a rake or tiller to work it in to a depth of about nine inches. Particularly sandy soil or soil with a lot of clay may need more amendments.
Permanent plants, such as trees or shrubs, also can benefit from the extra nutrient boost amendments provide. Sometimes it is sufficient to spread the material over the soil surface and let rainwater and wildlife help distribute it to the plant roots. Otherwise, work it into the top inch or two of the dirt with a hand cultivator.
Soil amendments can be the difference between a thriving garden and healthy landscape and one that has seen better days.