Growing herbs in Oklahoma can be a challenge. Most herbs require well-drained soil and full sunlight. Although Oklahoma has plenty of sun, the majority of the state has heavy clay soil. Heavy clay is characterized by lack of good drainage and by closely-packed, dense particles. Gardeners who wish to grow herbs in Oklahoma must either amend the soil or plant herbs in containers.
Choose a location for your herbs that gets full sunlight. A few herbs will tolerate partial shade, but most require full sun to thrive. Herbs that do not receive full sun will become spindly and will not produce.
Have your soil tested to determine itsstructure. Oklahoma State University maintains a Soil, Water and Forage Analytical Laboratory through the Oklahoma Cooperative Extension Service; it provides soil testing to the citizens of Oklahoma for a fee. To submit a soil sample, contact your local county extension service for instructions on collecting and packaging samples as well as fees and paperwork.
Purchase soil amendments based on recommendations determined by the test in Step 2. Most clay soil requires organic amendments such as compost to improve the structure and gypsum to aerate and improve drainage. Additionally, you can adjust the pH of soil: Add sulfur to lower the pH, or add powdered limestone to raise it.
Loosen the soil to a depth of 6 inches by inserting a spade into the sod to cut it up, then raking the cut sections of soil to break them up. Spread amendments over the soil to a depth of 3 inches. Mix the amendments into the soil with your garden rake.
Purchase herbs and herb seeds based on the USDA hardiness zone of your garden. Oklahoma falls between zones 6 and 7 of the USDA plant hardiness zones. Herbs such as garlic, chives, oregano, sage and rosemary will last throughout the winter and can be treated as perennial herbs. Herbs such as basil and parsley will not overwinter and should be planted as annuals.
Plant herb seeds in furrows that are twice as deep as the seed, two weeks before your last average frost date. Plant established herbs after the last average frost date of your region.
Water herbs well until they become established. The ground should remain as damp as a wrung-out sponge. Water in the mornings to prevent mold problems.