By Harriet Blake
Count yourself lucky if you live in a part of the country that has rich organic soil. Dirt in the Midwest and Mid Atlantic states tends to be easy to work with, while soil in warmer, drier Southwestern states requires some help. However, even if you live in an area with hard-to-work clay soil, there’s something that will enrich your dirt: organic matter, or compost. You can buy compost products at area garden centers, but consider taking advantage of what falls from your area’s trees. They provide free organic matter every fall.
Composted matter improves soil structure and drainage, says Texas A&M extension horticulturalist Keith Hansen. Compost also “promotes better root growth and increased absorption of rainfall and water, and helps reduce runoff, pollution and the loss of essential plant nutrients,” he said.
Soil organic matter helps a garden thrive. Good soil, as described in Organic Gardening from Rodale Press, has a high amount of organic matter, a loose, crumbly texture and a dark brown color. Organic additions to your dirt will make plants resilient, bigger and resistant to bugs and disease.
There are more than 20,000 kinds of soil in the United States, according to the U.S. Department of Agriculture, but the three basic types are clay, sandy and loam. The differences arise from an area’s climate, topography, parent material and biological factors (plants, animals, micro-organisms and humans).
Clay and sandy soil require additional organic material, such as compost or peat moss. Loosen up the soil by tilling or using a spade. Tilling compost, especially into clay soil, is essential before putting in a landscape, says Daphne Richards, a county extension agent with Texas A&M.
“Organic matter in the soil breaks up those hard, compacted clay lumps and allows air and water to flow through the soil, while also feeding beneficial microorganisms.” For already-established lawns that require “amending,” she suggests applying compost annually as a thin top dressing, allowing the grass to grow up through it. Clay soil takes a long time to absorb water, so water it slowly. The USDA advises watering only as fast as soil absorbs the water.
The addition of organic material in sandy soil also keeps water from running through the soil too quickly, which allows plants to absorb more moisture.
Loam soil, which is considered the best, is a combination of sand, silt and clay. It absorbs water easily and has the ability to retain it for plants to use later.
Bed preparation is key to any good landscape, according to landscape architect — aka the Dirt Doctor — Howard Garrett. “Without good bed preparation,” he says, “plants will struggle.”
Garrett recommends first removing unwanted vegetation. Get rid of weeds and grass, and toss
them into a compost pile. Don’t till the soil when it is wet, as this will eliminate air spaces that are important to good soil life, he said.
It’s important to raise beds to promote drainage. Moistening the soil before planting is key, but don’t make it so wet that the soil becomes muddy. For a new bed with no grass or an existing bed, Garrett advises adding 4 to 6 inches of compost, organic fertilizer, volcanic rock sand or powder and dry molasses. Then rototill, fork or air spade to an 8-inch depth. For a new bed located in a grass area, the existing sod should be removed to about 1½ inches and then add all of the above plus horticultural cornmeal. (Cornmeal can stop the germination of weed and grass seeds in the mix.)
After the beds are set, take pot-bound plants and gently loosen their root balls, taking care not to tear the root system. Dip the balls into water and put them into moist plant beds.
Adding compost tea – a low-strength natural fertilizer — is effective on many pests or problems, including black spot on roses. The plants should be set so the top of the root ball is even or just a bit higher than the soil level. When a plant sits too high, its upper roots dry out.
Make sure you add 2 to 3 inches of organic mulch after planting. Annuals and perennials need a thin layer of compost, while shrubs and ground cover benefit from mulch made of native tree trimmings.
Once your dirt is established, maintain its health by watering at the right time of the day, using the right fertilizer, mowing and using natural alternatives to keep pests away.
Watering in the early morning or night is best, as water evaporates when you use it during the day. Don’t water when it’s windy, so you can direct the water where it’s needed.
Fertilizing is important because plants need nitrogen (for healthy green growth); phosphorous (to help roots and seeds develop and avoid disease); and potassium (to allow root development and prevent disease). If applied correctly, these nutrients are absorbed by the plants and very little is absorbed by ground or surface water.
Because soils differ, having your soil tested to find out what type of fertilizer is needed is a good idea. Your local or state extension service should be able to help.
Remember to fertilize when dirt is damp, then water again after the application. This helps the fertilizer go directly to the roots instead of remaining on top of the soil where it can be blown away or washed away by rain.
When mowing – you’ve heard this before – leave the clippings on the lawn. They will decompose and provide natural nutrients for the grass. Also, don’t cut the grass too short during hot weather – you won’t need to water as much.
Natural alternatives for pesticides save money and are, of course, better for the environment. Spraying plants with non-detergent insecticidal soaps, garlic, hot pepper, a teaspoon of liquid soap in a gallon of water, used dishwater or a strong stream of water will help remove insects from your vegetation.
Also consider including plants that naturally kill bugs among the flowers in your garden. Some of these are mint (kills ants and aphids); onion (kills bean leaf beetles, spider mites and mice); garlic (kills flea beetles); French marigolds (kills root knot nematodes); and prostrate rosemary (kills slugs).
Everyone in the organic gardening movement can’t say enough about composting. The Dallas-based Clean Air Gardening news site notes that adding compost not only improves soil fertility but provides food for microorganisms to keep soil healthy and balanced. Nitrogen, potassium and phosphorus are made naturally by the feeding of microorganisms.
Understanding how to make and use compost is good for everyone. With landfills overflowing, composting provides an alternative to throwing away organic waste. Why toss away materials when they can be used to help your garden and lawn grow and thrive?