Introduced to the United States from Africa, okra (Abelmoschus esculentus) is an annual vegetable. Its immature pods are used in stir-fries, soups and stews, most famously in gumbo associated with New Orleans cuisine. Estimates of the best soil pH for growing okra vary but fall within a general range. If you have a growing season of at least 90 days after the last expected frost, you should be able to grow okra.
Appropriate Soil pH
Estimates by six universities or Cooperative Extension Services for the correct soil pH range for growing okra spanned from 5.8 to 6.5 on the low side to 6.5 to 7.5 on the high side. Utah State University Cooperative Extension, in an article on its website, put the ideal okra-growing pH range at 6 to 7. If your soil's pH level is within that range, okra should thrive in the soil.
About Soil pH
Soil pH measures the acidity or alkalinity of soil. Soil with a 7 pH is neutral. Soil below 7 is said to be acidic or sour. Soil above 7 is said to be alkaline or sweet. Soil in dry, arid climates is likely to be alkaline while soil in wet, rainy areas tends to be acidic. A soil testing kit can be used to measure soil's pH; most garden supply centers sell the kit. If your soil pH is significantly higher or lower, the soil can be amended to lower or raise its pH level.
Lowering of pH
You can lower soil's pH level by incorporating organic mulches, iron sulfate, sphagnum peat, aluminum sulfate, elemental sulfur or acidifying nitrogen with the soil. Sphagnum peat, an organic solution, has a pH of 3 to 4.5. Work a 1- to 2-inch layer of sphagnum peat into the top 8 to 12 inches of alkaline soil before planting okra. Granular sulfur is safe and less expensive to use, but it works slowly. If your soil's pH is 7.5, you can lower it to 6.5, which is acceptable for growing okra, by working 1/5 pound of elemental sulfur into 10 square feet of garden area. It is more difficult to lower soil pH if it is more than 7.5 because it may contain large amounts of calcium carbonate, which resists pH changes.
Raising of pH
Raise soil's pH by incorporating ground limestone with the soil. The amount to add depends on the soil's nature. Assume you want to raise the pH level to 6.5 in the top 6 inches of soil to make it good for growing okra. If the soil pH is 5, then add 8 pounds of ground limestone per 100 square feet of sandy loam, 10 pounds to loam and 15 pounds to clay loam. If your soil's pH is 5.5, add 6 pounds of ground limestone per 100 square feet of sandy loam, 8 pounds to loam and 10 pounds to clay loam. Loam is soil that contains roughly equal amounts of sand, silt and clay. Sandy loam contains more than one-third sand. Clay loam contains a larger amount of clay.
- Utah State University Cooperative Extension: Okra in the Garden
- University of Georgia College of Agricultural and Environmental Sciences: Growing Okra in the Home Garden
- Clemson Cooperative Extension: Okra
- University of Arkansas Division of Agriculture: Okra -- Home Gardening Series
- Mississippi State University Extension Service: Commercial Production of Okra in Mississippi
- Iowa State University Extension and Outreach: Horticulture and Home Pest News -- How to Change Your Soil's pH
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