Written by: De’Anthony Price, Agriculture & Natural Resources Extension Agent, UF/IFAS Extension – Jefferson County
Florida is the perfect place to grow sweet potatoes (Ipomea batatas). Sweet potatoes are considered a long-season crop, and Florida’s long, hot summers allow them to grow and mature well here.
Sweet potatoes are native to America and known for their colorful and tasty tubers. Their flesh can be yellow, orange, or even purple. They are a great source of vitamins A and C. Sweet potatoes are an excellent warm-season crop for Florida. They require a long growing season but will reward you greatly for your patience. The leaves are edible as well. Not only are they nutritious, but the young leaves and shoots also provide a source of tender and mild-tasting leafy greens through the hot Florida summer. Sweet potatoes are a healthier alternative to white potatoes with a high glycemic index. The starch from a white potato is quickly metabolized, leading to a rapid increase in blood sugar. Sweet potato starches are metabolized at a slower rate.
Planting and Care
Sweet potatoes can be planted in the spring through the end of June. Sweet potatoes grow in a well-drained loamy to sandy soil and do not require much fertilizing. If the soil contains clay, add some aged compost or other organic amendments to the planting bed to improve drainage. Sweet potatoes grown in unamended clay soils are usually small.
Sweet potatoes are generally planted from March through June in the Florida Panhandle. Sweet potatoes are typically started from transplants called “slips.” Sweet potato slips are six to eight-inch sweet potato vine cuttings with most of the leaves pulled off. You can purchase sweet potato slips from a local garden center or a seed catalog. Make sure you only buy certified, disease-free slips. One can also quickly start your sweet potato slips from a store-bought sweet potato. Sweet potato weevils can be a severe problem and starting with certified-free transplants can help you avoid issues.
Plant sweet potatoes in rows spaced 48 to 54 inches apart, with 12 to 14 inches between each plant. Look for transplants that are about 6 to 9 inches long. Sweet potatoes will do best when they receive a consistent water supply; inconsistent watering can cause them to split while growing. Sweet potatoes can be kept throughout the season using vine cuttings to create new plants.
Wireworms and root-knot nematodes are the biggest problems for home gardeners. However, many insect and disease problems can be avoided by choosing disease-resistant varieties and using sound cultural gardening practices. Crop rotation with a vegetable in another family can help prevent nematode and soil disease. Rotating where you plant can help prevent problems with a major pest, the sweet-potato weevil (Cylas formicarius).
For the tastiest sweet potatoes, always dig up the previous crop and start a new planting. While sweet potatoes can be grown year-round in tropical regions, plants left to grow for too long can encourage pest populations. The sweet potatoes eventually become too large and tough for most people’s tastes.
‘Centennial’ and ‘Beauregard’ are two varieties that grow well in Florida gardens. Beauregard is found quite often in garden centers. It shows some disease resistance and produces a high yield. It has light rose skin and a deep orange flesh that matures in 105 days. Centennial sweet potatoes tolerate clay soil, are disease resistant, and mature in 90 days.
Harvest and Storage
Sweet potatoes should be ready to harvest 90–120 days after planting. The tops will die back as it gets close to harvest time. Sweet potatoes should be harvested before the first frost. Cool soil reduces their quality and storage life. Sweet potato skin is fragile, so freshly dug roots need to be handled gently.
The ideal conditions for curing sweet potatoes are roughly 85°F with 90 percent humidity. To help increase their sweetness, place harvested sweet potatoes in a dark, warm room for at least two weeks before eating. Once your sweet potatoes are done curing, store them in a cool, dry pantry—not the refrigerator! Storing your sweet potatoes at temperatures below 50°F can cause them to have an off flavor or rot. Patience will pay off with delicious and healthy sweet potatoes that can be added to the dinner plate as a vegetable side or in a sweet pie served for dessert. While “yam” is sometimes used to describe the sweet potato, a true yam comes from a different plant.
People love eating potatoes, and farmers love planting them. Traditionally, Valentine’s Day is a known date for planting potatoes. This tradition goes back generations. Potato planting time in North Florida is during the coldest months of January to February, although February 14th is a popular planting day. The taste and texture of homegrown potatoes are far superior to those of store-bought spuds! Garden potatoes also provide a bounty of nutrients. The potato (Solanum tuberosum) is a member of the nightshade family. This cool-weather vegetable typically yields bigger crops in the northern portion of the U.S., however potatoes can be grown as a winter crop in warmer climates.
The most popular and successful varieties grown in Florida are based on yield, disease resistance, quality, and adaptability to warm climates. These varieties are white-skinned potatoes ‘Yukon Gold,’ ‘Gold Rush,’ ‘LaChipper,’ and ‘Sebago’, and red-skinned varieties ‘Red Pontiac’, ‘Red LaSoda’, and ‘LaRouge.’ For russet varieties, home gardeners can select varieties that mature relatively early (100-115 days), such as ‘Russet Norkotah.’ Exotic potato varieties are fun and interesting to try since these varieties are hard to find in supermarkets. They are often smaller, taking less time to cook, but are also very colorful, which can increase the nutritional content. Potatoes with bright orange flesh have more carotenoids, and those with red pigments have more anthocyanins, both having health benefits. Other fun varieties include fingerling types and varieties with blue/purple flesh. The ‘All Blue’ potato has deep blue skin and flesh and produces blue flowers. Certified seed potatoes are ideal and can be found at your local feed store or garden center.
Planting Prep: Before Planting
The seed potato needs to be cut into the size of an egg, with at least one eye per section. They must be dried in a cool, dark place for a few days. Plant the sections in a 4-6 inch deep trench that receives full sun, with the cut side down and sprouts facing up. Potato plants are heavy feeders and need nutrition through the growing season. To determine what kind and quantity of nutrients to apply to the soil, get the soil tested by a qualified laboratory. Contact your local Extension office for local fertilization recommendations. Apply a 10-0-10 fertilizer at 7.5 pounds per 100-foot row, both at planting and again 3-4 weeks later, by side-dressing fertilizer about 4-6 inches to either side of the plant.
Growing, Harvesting, Storage
Potatoes are ready to dig in about three months. Since potato tubers push up above the soil surface, the soil needs to be mounded around the stems as the plant grows. Tubers exposed to the sun turn green, making them inedible. Remove the tops 2-3 weeks before digging to “toughen the skin.” After harvesting, potatoes need to be kept in a cool (60-65 degrees F) dark place for 10-14 days to allow any damages to heal. Move them to a final storage location with high relative humidity, good aeration, and cool temperatures (38-40 degrees F). Washed tubers should be allowed to dry thoroughly before storing. Under proper conditions, potatoes can be stored for 3– 6 months or more.
Mulch provides nutrients to soil and plants, reduces weed growth, controls soil temperature, and improves the look of lawns and gardens. It gives the landscape a neat, uniform appearance and is an excellent Florida-Friendly choice for hard-to-mow areas and shady spots. One should keep a 2- to 3-inch-deep layer of mulch on plant beds. Always leave at least 2 inches of space around tree trunks to prevent rot. Create self-mulching areas under your trees by allowing fallen leaves to stay in place. Though bark and wood chips are typically the most common mulch, other forms are just as beneficial. The following are the best overall mulches for Panhandle gardeners!
Bark and Wood Chips
Bark and wood chips are frequently used on flower beds and around small bushes and shrubs. As they decay, the material provides nutrients to the soil. Both materials are inexpensive and can be found at most gardening supply stores. Cedarwood chips are popular for their repellent properties, keeping fleas and other pests away.
Pebbles and Rocks
Pebbles and rocks are effective in retaining soil moisture and minimizing weed growth. They are excellent mulch alternatives for flower beds. Rocks are economical in cooler climates, where heat retained by rock mulch can extend the growing season. Since rocks do not decompose, they don’t provide nutrients to the soil. If you’re looking for a nutrient-rich mulch alternative, rocks are not a good choice. This can be easily remedied by fertilizing your landscape to provide more nutrients. If you decide to use pebbles or rocks, keep in mind that they can be difficult to remove if you switch to a different type of mulch a season or two.
Leaves and Pine Needles
Leaves and pine needles are an affordable nutrient-rich mulch alternative. Rake and gather fallen leaves each season and redistribute them above your soil. For the best results, one should shred the leaves. Let the shredded leaves dry before adding them to your garden to reduce bacteria growth and pest infestations. Pine needles decompose and add nutrients to the soil, just like other organic forms of mulch. They work best with plants that prefer acidic soil conditions, like holly gardenias, roses, and chrysanthemums. You can buy bundles of pine needles at your local gardening store or gather them from your own trees and spread them around your garden.
Grass clippings are a cost-efficient alternative to traditional mulch. However, they must be dried out or composted before use to prevent potentially damaging heat from affecting plants. If you treat your lawn with chemicals, don’t use grass clippings in your flower or garden bed.
Compost is an affordable mulch alternative and enriches the soil by adding essential nutrients. Apply compost above your garden or lawn in a thin layer. Compost improves the soil, adding nutrients such as phosphorus, potassium, and nitrogen to your garden. One can make it yourself with discarded vegetable scraps, coffee grounds, dead leaves, and water.
Newspapers effectively keep weeds at bay, retain moisture, and regulate soil temperatures. Newspaper is equally functional compared to traditional mulches, but is not as visually appealing as other options. Moisten the newspaper slightly before laying it above the soil so that it stays in place. Then, add a thin layer of organic mulch on top. Apply five to eight sheets of newspaper at a time. If using newspaper without another mulch on top, shred it before applying it to your garden. Newspaper is biodegradable and will deteriorate like other mulches.