Rhubarb leaves are poisonous. If planting from seed, sow in early spring in rows 18 inches apart. Transplant roots the second year to their permanent location, 3 to 4 feet apart. 16 plants are needed for the average family of four. A packet of seed will produce about 20 roots, an ounce 100 roots. If planting roots, set them out in early spring 3 to 4 feet apart each way in full sun. Soil should be well-fertilized, light and airy. Roots may be cut moderately the first year and regularly thereafter. Does best in cooler climates. Sorry, we cannot ship to AZ, CA and HI.