In reality, this is zone 8 some years, zone 9 in others. With a last frost date of March 1st and first frost date of December 15th. The sweet potato is suitable for growing in zones 3-11 as an annual, and zones 8-11 as a perennial. Reply. Their growing range includes USDA plant hardiness zones 3 through 11. Here are … Jeanne May 24, 2014 - 1:24 am. Buy or obtain the roots of sweet potatoes (Ipomoea batatas) in early fall in U.S. Department of Agriculture plant hardiness zones 9 through 11. I live in the New Port Richey area and will be using a Smart Pot. Sun and Temperature Requirements. But since zone 9b has such a long growing season you don’t have to be as concerned about starting all your vegetables early indoors. When is a good time to plant my sweet potatoes. Sweet potatoes can be grown as perennials in U.S. Department of Agriculture plant hardiness zones 9 through 11. But growing sweet potatoes can be done even up in Alaska. You don't want the roots to face resistance when they try to expand within the soil. According to the new USDA zone map (which is a joke), we're solidly in zone 9. Articles on how to grow potatoes won’t help you here, because the crops are different from planting to harvest. However, they are almost always grown as warm-season annuals, and this is possible in all but the coldest zones. Do not immediately plant them outside, even if you live in zone 9, because they were probably raised in a greenhouse and need to be hardened off. Although sweet potatoes prefer conditions like those found in USDA Zone 8 and 9, gardeners in colder areas can grow them by choosing short-season varieties. Whether you decide to plant in beds or in grow bags, choose a spot that provides full-sunlight for most of the day. Zone 9 has a long growing season with hot summers. Sweet potatoes need loose, well-drained soil to form large tubers. Shelly. Growing in Cold Climates. Sweet Potatoes (from slips), 90-100 Of all the above vegetables some can be both direct seeded and transplanted. Before you plant sweet potato slips, you have a little extra work to do. These dates will vary a week or two so it’s important to watch the weather before planting. Zone 9 Fall Planting Guide June 27, 2020 Protect Sensitive Plants from Strong Summer Sun June 9, 2020 How to Grow Cilantro June 5, 2020 Loose soil is more critical than almost any other factor when it comes to growing sweet potatoes successfully. 2 Place sweet potato roots in a hotbed. Most vegetable varieties will have no problem maturing before your first frost date. Planting Sweet Potatoes.