Organic matter will boost garden soil. What to add and what to avoid

CORVALLIS The most effective method for improving almost any type of soil is to add organic matter.

If you’re not sure whether your soil needs additions, notice if it cracks and dries up in the summer, drains slowly, or is hard to dig in both wet and dry conditions. Even with extra water, do your rhododendrons and other plants wilt in hot weather?

Sand soils’ capacity to retain water and nutrients is enhanced by the addition of organic materials. Organic additions to clay soil enhance aeration and drainage, facilitating the soil’s rapid drying out and warming in the spring.

Compost, rotten manure, grass or wheat straw, and wood wastes like sawdust and bark mulch are all excellent organic supplements for garden soils. Verify that organic amendments have not been exposed to herbicides before applying them, as this can seep into the soil. Sand, pumice, perlite, and vermiculite are examples of inorganic amendments.

Although adding manure to your soil can be a wonderful way to increase its carbon content, it can take years for it to decompose. Adding fresh manure to an existing vegetable plot is not advised; instead, compost the manure before adding it. Combine manure stock with a nitrogen source, like vegetable scraps and grass clippings, to make compost. At least once every two weeks, or if the temperature has risen above and then dropped below 145 degrees Fahrenheit, try to turn this mixture into a 3-by-2-inch pile.

The main role of inorganic additions like perlite, sand, and vermiculite is to act as wedges, separating soil particles and enhancing soil aeration and porosity.

Finer silt or clay soils contract because sand does not retain water and nutrients efficiently. To enhance the amending qualities of sand, incorporate an organic amendment, such sawdust, into the soil.

Since organic matter will incorporate into the soil more quickly, tilling or discing it in can be advantageous. Avoid overtilling the soil, too, as this can result in a hard soil layer that inhibits drainage and root growth. The organic matter should be able to reach the soil’s subsurface level after one or two passes, which will allow the microbes to start eating it.

Planting a green manure cover crop is another simple method of amending garden soils. Crimson clover is a great winter cover crop for Western Oregon. For every 1,000 square feet, plant 12 pounds of seed. In order to establish the crop before the arrival of winter weather, plant by October 1st at the latest and irrigate the bed. Crimson clover will yield 3–4 pounds of nitrogen per 1,000 square feet when it is rototilled or disced under in late April.

“Improving Garden Soils With Organic Matter,” an Extension publication, and “Growing Your Own,” a helpful gardening manual for novice gardeners, offer more details on enhancing garden soils. A printed copy is available at the county extension offices.