“If you wait until spring, you forget what your garden needs,” says Felix Cutrone, a horticulturalist with Hicks Nursery on Long Island, N.Y.
Before you try to fix your soil, check it with a soil testing kit ($25), which will reveal soil pH and nutrient levels. Or, ask your local extension agent where to send soil samples for professional testing.
Soil that’s pH-challenged
Flower and vegetable gardens thrive with soil that’s not too acidic (low pH) nor too alkaline (high pH). Veer too far from neutral, and gardens will struggle.
- To raise soil pH: Spread garden lime pellets — ground limestone — evenly, rake into the top 2 inches of soil, then water. Lime will break down during winter and slowly raise the pH by spring.
- To lower soil pH: Add aluminum sulfate (your hydrangeas will bloom bluer) or cottonseed meal.
Size matters when it comes to soil particles. If particles are too large (sandy soil) water moves through too quickly and plants dry out; too small (clay soil) and water puddles and roots rot.
Both soil types benefit from generous helpings of organic material — leaf mold, compost, and straw.
“You just can’t add too much organic matter,” says George Pisegna of the Horticultural Society of New York. “It helps retain water and helps aid drainage.”
Cover crops, such as winter rye or alfalfa, add organic matter and break up soil to produce air spaces that roots love. Plant in fall and turn under in spring, 2-3 weeks before planting.
In need of nutrients
Soil tests reveal what nutrients your soil lacks and what soil amendments it needs. If your soil lacks:
- Nitrogen: Add compost.
- Phosphorous: Add aged manure, rock phosphate (mined from clay deposits), or bone meal.
- Potash: Add seaweed, manure, hardwood ashes, or granite dust.
Drainage impaired soil
Fall is a good time to change the lay of the land to solve drainage problems. Poor drainage causes root rot and turns your yard into breeding grounds for mosquitoes.
To lead water away from your garden, change the soil grade by building berms or digging a French drain. To prevent puddles within your garden, add topsoil to depressions.