How to Treat Alkaline Soil

Certain plants prefer alkaline soil over any other kind. However, most benefit more from neutral pH, which is why you should know the level that each of your plants prefers. Unbalanced pH is a common problem in the garden. If you ever run into this issue, here's how to treat alkaline soil:

Difficulty: Moderately Easy

Instructions

1. Pour 1/2 tsp of apple cider vinegar onto a wet soil sample, and If it fizzes, you definitely have alkaline soil. Get a home test kit for an exact pH reading. They're available at most home & garden stores. Plants that actually prefer alkaline soil include phlox, candytuft, lilac, juniper, and crape myrtle.

2. Reduce the pH of your alkaline soil if necessary. A pH of 7 is neutral; higher is alkaline and lower is acidic. You can decrease the pH by adding more acidic materials to your soil. To lower pH by one point: Use 5lbs. peat moss, 1.5lbs. sulfur, or 10lbs. aluminum sulfate per 100 square feet of soil.

3. Improve drainage so water can wash away alkaline salts. Just lay dead leaves and compost at the bottom of planting holes. Also mix coffee grounds or gypsum (1.5lbs. per 100 sq. ft.) in the soil to help even more. This is especially important for gardeners in Western states and high-rainfall areas.

Tips & Warnings

• Use smaller amounts of treatment for lighter, sandy soils.
• Use larger amounts of treatment for denser, clay-like soils.

Resources

• The Official Vegetable Gardener's Bible
• Gardening When It Counts: Growing Food in Hard Times
• The Gardener's Handbook of Natural Insect and Disease Control
• Trowel and Error: Over 700 Tips, Remedies and Shortcuts for the Gardener