Ideal pH Level for Green Bean Seed Germination
Green beans (Phaseolus vulgaris) are a warm-weather crop that prefers a rich, loamy soil for their shallow root systems. Growing green beans in optimal conditions will produce the most abundant and tasty harvest. Conduct a soil test before planting or transplanting to check for nutritional deficiencies and correct soil pH.
Ideal pH Level
A soil pH between 6 and 6.5 is ideal for green beans, according to the Iowa State University Extension, which is slightly acidic. When soil pH levels are less than ideal for plants, they have difficulty absorbing all of the nutrients they need, particularly nitrogen, potassium and phosphorous, all of which are vital for healthy foliage and root growth.
Test your soil immediately after it thaws and before you plant beans. To conduct a soil test, dig several holes spaced throughout your garden area, 1 to 3 inches in size. Mix all the soil samples together for the soil test. For a basic test, you can purchase litmus strips from a garden center to test pH levels. For a more detailed test, you may need to send your soil sample to be tested by an external company. Conduct the soil test before you add fertilizer or compost to your garden.
If your soil pH is not ideal for green beans, alter its pH level through a variety of amendments. If the pH level is less than 6.0, meaning it is too acidic for green beans, add powdered lime to your soil. Powdered lime can be purchased from home garden centers. The amount of lime needed will depend on how acidic your soil is. For example, a pH level of 5 to 5.5 will need 10 pounds of powdered lime for every 100-square feet of soil to raise the pH levels to ideal green bean conditions.
If your soil is too alkaline or the pH level is higher than 6.5, add sulfur to your soil. Sulfur can be purchased at garden centers. When a soil pH level is around 8, 2/5-pound of sulfur for every 10-square feet of soil is needed to sufficiently adjust the pH level.
- The Old Farmer's Almanac: Beans
- University of Illinois Extension: Beans
- Cornell University Cooperative Extension: Soil Testing
- Cornell University Cooperative Extension: Correcting Soil pH
- Iowa State University Extension and Outreach: How to Change Your Soil's pH
- Reader's Digest New Zealand: Correcting Soil pH
Paul Schuster began writing in 2006 and has published in "Gardening Life" and "Canadian Gardening." Schuster is the director of the Toronto Botanical Garden, and holds a Bachelor of Science in Agriculture and Horticulture from the University of Guelph. He leads gardening workshops for elementary school children.