How do I improve poor soil for edibles?
Written by
Benjamin Miller
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Enhancing bad soil begins with understanding your particular conditions, whether they be heavy clay soil or sandy soil. Test your drainage by digging a hole, filling it with water, and timing how long it takes for the water to be absorbed. Damp clay soils drain slowly, while sandy soils dry too quickly. The knowledge acquired guides your amended soils so that they will yield the healthiest edible growth.
For heavy clay soils, amend with generous amounts of organic compost mixed with coarse sand. Use three parts compost to one part sand per square foot per year. This combination enhances drainage and supplies nutrients. For best growth, mix six to eight inches of this material before planting.
Clay Solutions
- 3:1 compost-to-sand ratio
- Add gypsum to break up compaction
- Incorporate shredded leaves annually
Sandy Fixes
- 2:1 compost-to-soil ratio
- Mix water-retaining coconut coir
- Add bentonite clay for moisture
pH Adjustments
- Elemental sulfur for blueberries
- Lime for asparagus beds
- Coffee grounds for acid-loving plants
Check the pH of the soil using inexpensive kits, as different foods require varying acidity levels. Blueberries require an acidic soil with a pH of less than 5.5, while asparagus will flourish in neutral soil, which has a pH of about 7.0. Adjust with elemental sulphur to lower the pH and with garden lime to raise it. This should be applied in small amounts until the desired results are achieved, checking the soil pH every three weeks.
For immediate solutions to problem areas, consider installing raised beds with custom soil blends tailored to your specific needs. Frame with untreated wood or stone, and fill with equal parts of topsoil, compost, coarse sand, or perlite. These beds warm up so quickly in the spring, provide perfect drainage, extend the growing season regardless of ground conditions, and yield a color that is found in nature itself.
Use care of soil through mulching and cover crops. Plant winter rye or clover "off season," to prevent soil erosion and increase organic matter. Apply a three-inch layer of mulch annually, using straw or shredded leaves as the mulch material. This means conserving soil health, so fewer amendments will be needed in the future, and the soil moisture will be conserved.
Watch for what plants tell you; they're the ultimate indicators of soil health. Yellow leaves indicate an incorrect pH level, while stunted growth suggests soil compaction. My blueberries went crazy when I added pine needles, while carrots straightened out in my raised beds with sandy loam. These are the amendments I am referring to.
Read the full article: 10 Essential Edible Landscape Design Tips
