For many people in the Panhandle, gardening season begins when the weather warms in spring and nurseries start setting out tomato transplants. While I understand the allure of the yummy summer veggies and spring/early summer are the most traditional times to garden, cultivating a winter garden in the Panhandle unlocks many tasty options. Among these cool-season garden veggies is a classic southern staple that is among the easiest and most rewarding of all vegetables to grow, sweet onions!
‘Texas Super Sweet’ Onions almost ready for harvest in a Calhoun County garden. Photo courtesy of Joe Leonard.
Sweet onions are very popular in the culinary world for their mild flavor and soft texture and are among the most widely grown group of onions across the world, but the most famous of them, Vidalia’s, hail from Georgia! Despite its fame, the “Vidalia” onion is actually nothing more than a trademarked name for a specific variety of sweet onion that was bred in Texas (‘Yellow Granex’ and its derivatives), grown in a 20-county region in South Georgia with excellent onion-growing soil, and made famous by excellent marketing from the Vidalia Onion Committee. While they can’t be called Vidalias legally, you can absolutely grow your very own Vidalia type sweet onions at home here in the Florida Panhandle!
Sweet Onions are most easily grown at home if purchased in the fall as “sets”. Sets are small bulbs that have been started, harvested, dried to prevent rotting during storage, and shipped to garden centers ready to be “set” out in home gardens. Sweet onions may also be grown from seed but take much longer and have a lower success rate. When browsing onion set varieties for purchase at garden centers or in seed catalogues, make sure to purchase a short-day “Granex” type like “Texas Super Sweet” or similar. It is critical to remember that sweet onions are classified by how many hours of daylength they require to produce bulbs. The three classifications are Short, Mid, and Long-Day. Since sweet onions require cool weather to develop properly, Floridians must grow short-day varieties to compensate for decreased daylight hours in the winter. In the less hot Northern states, long-day sweet onions are grown in the summer, where they’ll be able to soak up 15-16 hours of daylight. Therefore, for best results in the Panhandle, select ONLY short-day onion varieties.
‘Texas Super Sweet’ Onions that have been harvested and are ready for use! Photo courtesy of Daniel Leonard.
Once you’ve selected your onion sets in the fall, they can be planted in the garden anytime from early October to mid-December. Individual bulbs should be planted about an inch deep in well-drained garden soil with high organic matter content (mushroom compost, composted manure, or other rich organic matter works) and spaced 4-6” between plants and about a foot between rows. Onions in general, and sweet onions in particular, are heavy feeders and require ample nutrition to meet their potential! To meet these fertility needs, I apply a slow-release fertilizer like Osmocote or a Harrell’s product at planting and supplement that with either a quick release granular or liquid fertilizer monthly during the bulb enlargement phase. Sweet onions also have a shallow root system and require frequent watering to develop properly and avoid splits, doubles, and small bulbs. Don’t let your onion bed dry out!
Finally, sweet onions planted in late fall/early winter are normally ready to harvest in April and May. However, rather than relying on a calendar, begin harvesting your onions when the tops start to turn yellow and fall over, this indicates maturity. After harvesting, allow your onions to “cure” with tops and roots still attached for a couple of weeks outside in a shaded, protected area. Once they’ve had an opportunity to “cure”, remove tops and roots and store the cured bulbs in a cool, dry place (a dark pantry in an air-conditioned room or the refrigerator crisper drawer work fine) and use at your convenience!
While they can’t be called Vidalias, sweet onions grown at home are oh so rewarding and very tasty! Provided they are planted in quality soil, receive plenty of water and fertilizer, and are harvested/stored correctly, sweet onions will provide a delicious, home-grown culinary treat throughout the year! For more information about growing onions in the home garden or any other horticultural/agricultural topic, contact us at the UF/IFAS Calhoun County Extension Office. Happy Gardening!
Use frost cloth to completely cover cold sensitive plants. Be sure to make complete contact with the ground and use heavy objects to keep the fabric secure. Photo by Jonathan Burns.
One major aspect that separates North Florida from South Florida is the discrepancies in air temperature. Although the differences are relatively small when comparing Florida with northern states, they can mean a world of difference in the plant world.
Even hardy cauliflower leaves can be damaged by cold winter nights in the Florida Panhandle. Photo by Molly Jameson.
In most of North Florida, our USDA plant hardiness zone is 8b, which means average minimum winter temperatures are between 15 and 20° Fahrenheit (F). We therefore can experience hard freezes, which happens when temperatures are below 28°F for over five hours. These types of conditions are capable of “burning” the leaves of even the toughest winter vegetables.
Fortunately for our winter gardens, average minimum winter temperatures are in the lower 40s, high enough not to damage winter garden crops. When we do have lows close to or below freezing (32°F), there is one very cost-effective method that can help keep crops and landscape plants protected. This is the use of a material called frost cloth.
Frost cloth can moderate air temperatures six to eight degrees. Photo by Turkey Hill Farm.
Frost cloth, which can be purchased at most plant nurseries, is a breathable polyester fabric that is light weight and heat retentive. When used correctly, it can moderate air temperatures about six to eight degrees. This is typically all that is needed to get us through our mild North Florida winters. It is also relatively inexpensive, and if cared for, the same cloth can be used for many winter seasons.
Large blankets or bedsheets can be used as frost cloth substitutes, but whether you are using actual frost cloth, or something pulled from the linen closet, it is very important to use it correctly to be effective. The cloth must touch the ground at all points, as it works by trapping heat that radiates from the soil. It also increases the humidity around the plant, aiding in temperature moderation.
“Lollipop” trees will allow the heat from the ground to escape, giving the tree no cold protection. Photo by Jonathan Burns.
For sensitive landscape plants and fruit trees, it can be more difficult to fully cover the plant with the frost cloth to trap the heat, but it is just as important. When driving around town on a cold night, I inevitably encounter a few “lollipop” trees. This is when the foliage of the tree is wrapped in frost cloth, but the cloth does not reach the ground, and is typically tied off at the upper trunk of the tree. All heat moving upward from the soil will go right around the cloth, giving the tree essentially no protection.
Wire or PVC hoops can be used to help secure frost cloth and keep the cloth from damaging sensitive plant stems and leaves. Bricks, sticks, soil, or garden staples should be used along the perimeter of the frost cloth to prevent nighttime gusts from blowing the cloth off your garden beds or landscape plants. In the morning, remove the cloth once air temperatures reach about 50 to 60°F.
To learn more about cold protection, check out the UF/IFAS EDIS publication, Cold Protection of Landscape Plants (https://edis.ifas.ufl.edu/publication/MG025).
Fall is the season for leaf color changes on many plants, but we are often concerned when we see evergreen plants with brown leaves. Learn what is normal browning for evergreens and when to seek more help from UF IFAS Extension Escambia County.
As you garden this fall, check out the North Florida Vegetable Gardening Guide, compiled by UF/IFAS Leon County Extension.
Getting into vegetable gardening, but don’t know where to start?
Even experienced gardeners know there’s always more to learn. To help both beginners and advanced gardeners find answers to their questions, the UF/IFAS Leon County Extension Office put together the North Florida Vegetable Gardening Guide. It incorporates multiple resources, including articles, planting calendars, photos, and UF/IFAS EDIS publications.
The North Florida Vegetable Gardening Guide covers the many aspects of vegetable gardening, including how to get started, site selection, insects and biodiversity in the garden, soil testing, composting, cover crops in the garden, irrigation, and more.
You can click here to view the digital version of the guidebook. We also have physical copies of the guide available at the UF/IFAS Leon County Extension Office (615 Paul Russell Rd., Tallahassee, FL 32301).
Happy fall gardening!
As October gets by us and November quickly approaches, I would like to include the preparation on What to Plant? And What to Do? Some great annual plant choices are digitalis (foxglove), petunias, and Shasta daisy. There are many daffodil bulb varieties for North Florida including the following: Carlton, Fortune, Silver Charms, Thalia, and Sweetness. We will be getting into more of the cooler days, so this is a good time to start bulb onions and salad crops such as arugula, lettuce, and spinach. Dill, fennel, oregano, and sage are all herbs that can be planted throughout the fall months.
Start preparing now so your fall garden will be full of dark leafy greens, multi-colored lettuces, and root vegetables of all shapes and sizes. Photo by Molly Jameson.
In lawns there are a few key things that can be done in October. It is possible to control winter weeds before they appear. This is the time to use preemergent herbicides when nighttime temperatures are between 55-60 degrees Fahrenheit for four to five days in a row. If a green lawn is desired, you can overseed with annual ryegrass when the daytime temperatures are in the low 70s. Remember, the lawn will still need to be watered and mowed to maintain a healthy ryegrass. Watch for fungus like brown patch and large patch disease. This can become active when the soil temperature is between 65-75 degrees Fahrenheit.
Hollies also attract bees to the landscape.
Credit: Beth Bolles, UF IFAS Extension Escambia County
And last but not least as you prepare for winter around the corner you can plant evergreen hollies that will make it through the cold and provide a splash of color with red berries. Gather pine needles that are dropping and use as a natural mulch, and this is the last month that strawberry plants can be established in a bed or a large container.
There are some key practices that are necessary to make sure your trees and shrubs establish and thrive in your landscape. Learn a few pointers from UF IFAS Extension Escambia County to promote healthy establishment after correct plant installation. Learn about installing shrubs with the UF IFAS publication Establishing Shrubs in the Florida Landscape.