To grow a cumin plant, place potted seeds in a sunny location, use well-drained soil and water it regularly. Unless you live in an area where temperatures are 60 to 85 degrees Fahrenheit for at least three months, start the seeds early indoors, and transplant them once the weather warms up.
Choose an outside location that receives full or partial sun and well-drained soil. Before planting, work 1 inch of compost into the top couple inches of soil, and dig shallow 1/4-inch holes that are up to 6 inches apart. If planting the seeds indoors, use biodegradable pots that are 4 inches deep and 6 inches in diameter filled with seed-starting potting mix. Sow the seeds in holes that are only 1/4 inch deep. Place the pots in a plastic closed bag, and open it every day until the seeds sprout to keep the soil moist.
Give the seed or seedling 1 inch of water per week, enough to soak the top 6 inches of soil, and water it from the soil to avoid wetting the foliage. Once the seedling reaches 6 inches tall, snip off the stems at the nearest leaf node to increase flowering and seed production from which the cumin is derived. Once the flower seed heads completely dry out and turn brown, cut them off, and store them.