Looking to add a nutritional powerhouse to your early season garden this year? One plant that is often thought to be difficult to grow in Florida will surprise many home gardeners. This plant has a long, storied history, having been introduced extensively worldwide, and has invigorated and decimated entire populations. I speak, of course, of the humble potato (Solanum tuberosum), which performs well in our cooler North Florida winter. This member of the Solanaceae or nightshade family can trace its origins to the Andes mountains, where it was discovered by European settlers and brought back to their countries of origin. From there, the potato found success as a food crop and was reintroduced worldwide. This tuber is a big producer, and worthy of a spot in your home garden.
Varieties
The first objective with potatoes is to find a variety that will perform well in our sandy soils and climate. Russets are thought to be the gold standard in potatoes, and while some may be suitable, they are not optimal for Florida gardens. Instead look for some of the later entrants to this market. Several white and red varieties are available which mature quickly and can tolerate environmental conditions in the panhandle. White varieties suitable for this region are ‘Lachipper’ and ‘Sebago’, while the red varieties known to do well here are ‘Red Lasoda’ and ‘LaRouge’. These are compatible with our environment and as such perform well here.
UF/IFAS photo: C. Hutchinson
Growth Practices
A well-draining, slightly acidic, and loose soil will provide the best environment for maximum yield. As with all gardening, it’s best to have your soil tested well before you plant and make any pH adjustments required early. Potatoes grow from “seed” which are essentially smaller potatoes grown specifically to produce more plants. It’s best to acquire these from a reputable seller and avoid grocery store leftovers, as their variety and disease resistance is questionable. Growth happens from the “eye” of the seed, which may be planted with or without growing roots. Cut the seeds into smaller pieces, ensuring there is at least one eye per piece, and allow them to sit in a cool, dark environment for a few days to callous over. They are now ready to plant and should be four inches deep, spaced eight inches apart in three-foot rows. Potatoes require two fertilizer applications, emphasizing nitrogen and potassium specifically, as these pass through the soil easily with irrigation. Apply half of the fertilizer at planting with another application approximately 30-40 days later. Application rates vary and are based on yield goals as well as soil test results so check with your local extension agent to discuss application rates. Keep the potatoes evenly moist but make sure not to flood the rows. Finally, there is a unique methodology with potatoes in that you’ll need to add soil to the top of the row when the potatoes poke through. This is called hilling and is crucial to keep the tubers from turning green and producing a toxin known as solanine.
UF/IFAS photo: C. Christensen
Harvest Time
Your potatoes should be harvestable in about 90-105 days, depending on variety and environmental factors. You’ll be able to tell the plant has matured as the vines will begin to die back naturally. Modern practices have augmented this to include a vine kill which may be performed mechanically or through chemical application. This will force the tubers to mature, allowing the gardener greater control of harvest times and helping to avoid the risk of late-season pathogens. Vine kills are performed between 80-90 days after planting with tubers remaining in the ground for an additional 21 days. All of these time frames are dependent on variety but will produce a more usable and easy-to-store tuber.
UF/IFAS photo: C. Christensen
Potatoes are a worthy addition to the garden and can provide a lot of nutrient-dense food in a small space. There are a few tricks to growing these tubers, but for what they give back, you’ll find it a very rewarding experience. For more information, see these Ask IFAS documents. As always, please contact your local extension agent for additional information on this and any topic regarding your gardens and more.
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.
Sweet potatoes are ideal for filling the gap between summer and fall crops as they have a long growing season. Photo by Janis Piotrowski.
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).
Damage to sweet potato tuber caused by larval feeding of the sweetpotato weevil, Cylas formicarius. Photo Credit: James Castner, University of Florida.
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.
Florida-friendly varieties
‘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.
Potato Varieties
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.
Credit: C. Christensen
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.
Typical Hollow Heart condition as seen on this Red Lasoda potato. Image Credit: Matthew Orwat, UF/IFAS
One of the most frustrating things about gardening is finding something wrong with a crop that cannot be fixed. I witnessed this last week when checking on a problem with some recently harvested potatoes.
Sometimes potatoes that look perfect on the outside might not be perfect on the inside. Unfortunately, this is the case when potatoes are afflicted by the physiological disorder “hollow heart” or “brown center”.
The disorder that causes hollow heart or brown center in the potato tuber manifests when cells die inside while potatoes are growing too quickly or unevenly, such as when recovering from environmental stress or over fertilization.
Weather extremes during tuber development cause plant stress. Weather conditions that may cause brown center are early season cool nights, which cause soil temperatures to be below the mid-50s for around a week or longer. Soil moisture at 80% or greater may also cause the same brown center symptoms.
Typical Brown Center condition as seen on this Red Lasoda potato. Image Credit: Matthew Orwat, UF/IFAS
Hollow heart is typically caused by swings from low to high soil moisture and overapplication of nitrogen. To mitigate this condition, consistent irrigation practices and spit fertilizer applications have been shown to be effective.
Additionally, if hollow heart or brown center is a typical problem for a given growing area, selection of cultivars that are less susceptible to this condition is beneficial, since there is quite a bit of variation among cultivars / varieties.
The final message is one of good news, if brown center or hollow heart is noticed at potato harvest this year, there are steps that can be taken to mitigate this issue for future growing seasons.
Violas. Photo Credit: University of Florida/IFAS Extension
It is freezing cold this week and hard to believe that we are already talking about “What to Plant” and “What to Do” to get started early. In North Florida there are cool-season annuals that can be planted now. The list includes pansies, violas, petunias, and snapdragons. As we are coming to the end of January it is time to plant crinum, agapanthus and gloriosa lily bulbs. Make sure to mulch these areas after planting to protect them from the cold temperatures. This is also the month to plant camellias, which these come in many colors and forms that your local nurseries will carry this time of year. If you haven’t planted all your cool season crops there is still time to do that now such as broccoli, kale, carrots, and lettuce. Irish potatoes can be planted now as well.
Now you might be asking “What can I do?”. January is a great time to prune non-spring flowering shrubs and trees to improve their form. This is a good time to plant deciduous fruit trees, this will give their roots time to develop before the warmer spring temperatures. Since existing trees are dormant, it is a good time to prune and fertilize them. When the temperatures are near freezing many of the tender plants will need to be covered to minimize damage. It’s a good time to plant a tree. Hurricane-resistant trees include live oaks, bald cypress, cabbage palms, and southern magnolias. It’s time to remove those dead spent seed pods on your crape myrtles and removing any crossing branches and twiggy growth will improve the appearance and the form of the plant.
Potatoes planted in mid-February were ready to harvest in mid-May in Bay County. Photo: Vicki Evans, UF/IFAS Master Gardener of the plant.
As we go into February it will soon be time to apply a preemergence weed killer to your lawns to prevent warm-season weeds. Temperatures must rise to 65°F for 4 to 5 consecutive days before you do a preemergence application and make sure you are not using a weed and feed fertilizer. Citrus and other fruit trees can be fertilized at this time. The amount and frequency will depend on the age and type of fruit tree you are growing. Avoid pruning Citrus until spring to avoid any injury since cold temperatures are still possible. It is time to prune those roses this month to remove damaged canes and improve the overall form. After the pruning is complete you can fertilize and apply a fresh layer of mulch. They should begin blooming within 8 to 9 weeks after being pruned.
Dianthus, pansies, violas, and dusty millers are annuals that can take a chill and should be planted in February. You can continue to plant crinum and agapanthus this month and add on amaryllis and rain lily bulbs as well. If it has been dry make sure to provide plenty of water for the bulbs to establish and continue to protect them from the cold by adding mulch. Trees and shrubs will begin to bloom this month including red maples and star magnolias. Continue planting potatoes throughout the month and towards the end of February warm-season crops like tomatoes and pepper can be planted but be prepared to protect them from any late frosts.
