Till the soil in your seedbed to a depth of 6 to 10 inches. Add enough organic matter like compost, peat or aged manure to cover 1 inch of the bed and thoroughly mix it into the native soil. Rake the bed and remove any large dirt clods.
Plant foxglove seeds in late summer if you live in a climate without snow. If you live where it snows, plant the seeds as soon as the ground is workable in spring. Sew seeds at a depth of 1/2 inch. Spacing is not important at this time.
Thin seedlings so they are 1 to 2 feet apart. Colorado State University recommends thinning foxglove to a fourth of its mature height. Using this formula, spacing depends on the cultivar you're planting and how large it will be at maturity.
Apply 1 inch of water weekly during the growing season. Water if the soil gets dry in winter.