We have two types of soils here in the Aiken area; you are blessed with either a light sandy soil or a heavy clay soil. Both of these soils have their advantages; sandy soils drain well and won't drown your plants' roots, and clay soils are highly fertile and can produce wonderful crops. But both of these soils have drawbacks as well; our sandy soils are extremely infertile, and our clay soils are most often compacted and therefore difficult to handle in the garden. Interestingly enough, the strategy for addressing the drawbacks of both sand and clay soils is the same: Add organic matter (compounds that come from plants and animals and their waste). As gardeners, we hear this advice again and again, whether it is advice for planting ornamentals or installing a vegetable garden. This is a process that has been going on in a natural way since the beginning of time; leaves fall, plants die, and soil forms.
At a recent seminar Karen Brady, a Resource Conservationist here in Aiken, encouraged gardeners to view soil from a biological perspective rather than a chemical perspective. Our soils are ecosystems that are inhabited by visible animals and insects (earthworms, ants, etc.), and microscopic animals (bacteria, fungi, nematodes, etc.). Like all animals and insects, some of these soil inhabitants are beneficial to us and some are considered pests. Many beneficial soil microbes have been found to assist plants in water and nutrient uptake; you can read more on this subject in Teaming with Microbes by Jeff Lowenfels and Wayne Lewis, a highly recommended book for a more technical and lengthy discussion on soil biology and chemistry. For the sake of this article, it is enough to know that soils are a living environment, and they benefit from the addition of organic matter.
Of the three components of soil (sand, silt, and clay), sand is the largest particle. Water flows through sand easily, so the addition of organic matter aids in slowing that flow down and will increase the water retention of your sandy soil. Because water flows through sand so quickly and easily, sandy soils are infertile because the flowing water carries soil nutrients away with it. By adding highly-fertile organic matter to your sandy soil, you will add nutrients to the soil and create an environment where soil microbes are actively doing their job of slowly breaking down nutrients for plants. Organic matter is the best natural “time release fertilizer,” and the microbes in the soil are the agents that break down particles to release nutrients.
Clay is the smallest soil particle, and therefore clay soils are often compacted. Small clay particles form a dense soil that doesn't drain well, and doesn't allow much room for root growth either. The addition of organic matter in clay soils increases drainage, makes room for oxygen in the soil, and creates room for roots to grow. It also adds to, and feeds, existing soil microbes that will transfer nutrients to your plants. Moisten your clay soil to loosen it up and work organics into it. North Carolina State University recommends that you specifically avoid adding sand to clay soils because any mixture that is less than 70 percent sand packs more densely than straight clay. Adding sand to clay makes a readily compactable soil that isn't suitable for gardening.
If you decide to add organic matter to your garden you have many choices, including compost, leaf mold, composted manure, green manure (cover crop), and crop residues. After years of home composting, I believe that the most important step in composting is the first one - just get started. Follow Felder Rushing's two rules for composting: gather your materials and pile them up. It doesn't have to be fancy; it doesn't have to follow a specific formula; and it doesn't have to be intimidating. Just collect your yard refuse (plant debris, chemical-free grass clippings, fallen leaves), mix it with your kitchen waste (no dairy or meat products that will attract animals), and pile it up. Over time it will decay and give you a wonderful amendment for your garden soil. It works! After you get started and have had some success, do your research to improve your efforts or to help choose a bin that works for you.
Organic matter can also be purchased in the form of bagged top soil, compost, soil conditioner, or bulk compost by the pick-up truck load. Cover your garden with a 3-inch layer of organic matter, dig it into the top 6 to 8 inches of soil, plant your vegetables or ornamentals, cover the surrounding soil with newspaper (4 to 8 layers thick) to prevent weeds, and finish off the garden with 3 inches of mulch. While this process sounds like a lot of work, you will save yourself time and effort in the long-run by reducing watering and weeding. Try this technique in only a small area this spring; reap the benefits of your efforts, and enjoy the garden!
Upcoming Aiken Master Gardener events
Spring is in the air and gardeners are getting busy! A popular service of ours is the “Rent a Master Gardener” program. For a nominal fee, a team of 4 to 6 Master Gardeners will visit your home to answer your questions and examine your lawn and garden for problems you may not see. After the visit, you will receive a detailed report listing our findings and offering suggestions on how to improve your landscape. Call our office at 803-649-6297 for more information or to schedule a visit.
The Meet a Master Gardener team will be at the Aiken Farmers Market (on Williamsburg Street between Richland and Park) on Saturday, April 5 from 8 a.m. to noon to answer your gardening questions and to present a demonstration on southern turf grasses and their care. Samples of turf grass and common turf grass weeds will be on display.
We are busy preparing for our annual plant sale, which will be held on Saturday, April 19, 2014 from 9 a.m. to noon at Trinity United Methodist Church, 2724 Whiskey Road on the south side of Aiken. Plants for sale will include iris, tomatoes, peppers, hydrangeas, begonias, salvias, cannas, and garden mums. New this year is a “garden gift” area where we will sell hand-crafted garden items like stepping stones, mixed ornamental containers, and slate garden signs.
If you have questions about these events or any lawn and garden topics, call the Aiken Master Gardeners at 803-649-6297 ext. 122; send an email to firstname.lastname@example.org; or visit us weekday mornings in our office at 1555 Richland Ave. E.
Pam Glogowski moved to Aiken in 2001 from Janesville, Wis., and has been an active Master Gardener volunteer since 2007.