There are important landscape lessons to learn from recent, early and widespread freezes.
First, know the average climate for the region you live in here in Florida. The work has already been done for you with the USDA Plant Hardiness Zone Map. Here is a link for the map: https://planthardiness.ars.usda.gov. Find your zone on the map. Note that Northwest Florida includes zones 8a, 8b and 9a.
The newest map, with interactive features, was updated in 2012.
This map is based on the average annual minimum winter temperature and is divided into 10°F zones. It can help you determine which plants are most likely to thrive in your zone. There are areas bordering Alabama, located in the extreme northern portions of Escambia, Santa Rosa, Okaloosa, Walton and Holmes Counties, that are in Zone 8a, with an average annual extreme minimum temperature of 10 to 15 degrees F. Most of these counties fall within zone 8b, with an average annual extreme minimum temperature of 15 to 20 degrees F. The extreme southern portions of these same counties (bordering the Gulf) are in Zone 9a with an average annual extreme minimum temperature of 20 to 25 degrees F. As you go south in Florida, you move into Zones 9b, 10a, 10b, and 11a. Zone 10b has an average annual extreme minimum temperature of 35 to 40 degrees F. Zone 11a; which includes a small portion of West Palm Beach and Fort Lauderdale, most of Miami and all of the Florida Keys; has an average annual extreme minimum temperature of 40 to 45 degrees F.
Most of the Panhandle is in USDA Hardiness zone 8b.
It seems that some people move to extreme north Florida and think they are in extreme south Florida. They move barely below Alabama or Georgia and want to plant the palms, citrus and tropical plants that thrive in extreme south Florida. If you live in Zone 9a, perhaps you might get by with growing a few plants that are well suited for 9b. But it is wise to mostly grow plants that are known to flourish in the Plant Hardiness Zone where you live.
Secondly, follow principle one, which is Right Plant, Right Place, as explained in the UF/IFAS Extension Florida-Friendly Landscape™ (FFL) Program. Following this principle results in developing a healthy, low-maintenance landscape by using Florida-Friendly plants that match your site’s soil, light, water and climatic conditions and that require limited supplemental irrigation, potentially less fertilizer and fewer pesticides.
More information on the FFL Program is available through this UF/IFAS Extension link (https://ffl.ifas.ufl.edu) or from the Extension Office in your County.
Using these tools may be a great goal for 2023 as we replace cold-injured plants.
Cold damage on kumquat. Photo by Beth Bolles, UF IFAS Extension Escambia County.
In December, winter rolled in with extreme low temperatures that affected landscapes across Florida. Horticulture Agents have been receiving a high volume of calls asking about the long-term fate of landscape plants impacted by the cold, so the Gardening in the Panhandle team decided to offer a special episode addressing these concerns.
Gardening in the Panhandle LIVE! Special Episode Freeze Damaged Landscapes will be held on Thursday, January 12, 2023, at 12:15 p.m. CDT/1:15 p.m. EDT. We will follow our usual format where the audience can join on Zoom, Facebook, or watch a recording on YouTube. The only change is that this program will be condensed to 30-45 minutes, rather than a full hour.
Freeze warning is a terrifying phrase for gardeners. Cold damages your plants and may even kill them outright. Understanding how plants freeze will help you create mitigating strategies for their preservation. Informing yourself as to how freeze damages plant tissues will allow you to fortify your garden.
How do Plants lose Heat
Cold exposure happens in a couple of ways. Radiant heat loss occurs when one surface emits waves of heat into a colder surrounding environment. The surfaces of leaves and stems are not immune to this type of temperature transfer, nor is the soil in your garden beds. Frost may or may not form depending on moisture levels in the air, but cold damage will still be the result. The other main source of heat loss in gardens is through Advective freezes. These occur when cold air from the north moves south en masse resulting in colder temperatures and often increased winds. Mitigating this is a little tougher than radiant losses but not impossible
IFAS Photo
As with all things, planning is at the forefront. When designing your garden, cold hardiness should be considered. Certain plants naturally handle cold weather better than others. Utilizing native plants and those specified for your USDA hardiness zone will keep gardens alive in winter months. These tend to be acclimated for colder temperatures. Once the proper plants are selected and planted, ensure they are properly treated. Keeping your plants as healthy as possible is also critical in cold tolerance. Mulches and watering prior to a freeze event will reduce risk from radiant heat loss. The water absorbs warmth through the day and holds onto it more efficiently than dry soil would. Addition of a frost blanket will further reduce heat lost and ultimately the damage to your plants. A slightly more in-depth protection method comes from establishing microclimates in your yard. Use taller trees and windbreaks. Taller trees create a canopy that blocks heat loss to the atmosphere. Windbreaks keep the colder air away from your gardens and again prevent heat loss. None of these methods are fool proof but will help keep your gardens alive through the colder months. You may still experience damage from freezes. If this does happen, make sure your plants are watered to thaw any roots ensuring they function properly. Inspect stems by scraping a little tissue. Prune away any that shows black or brown tissue while keeping any which still looks green.
IFAS Photo
Summing up
Freezes can be devastating to your gardens. A little knowledge can go a long way toward mitigating loss. For more information on cold protection, see this Ask IFAS document, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.
Have you ever visited a public garden or a park and wondered what type of plant you were looking at? Or found the name on a sign but wondered – can I grow that at my house? How big will it get? Does it have flowers, berries, keep its leaves in the winter? We feel your pain, fellow plant lovers!
Gardens are ever evolving and providing up to date printed information on all the plants can become difficult to manage and involve a lot of wasted resources. In Bay County, we have several gardens at the Extension Office, and we try to keep everything labeled, but space on signs is limited to plant name and we want to teach gardeners how to grow not just identify plants. To expand outreach of Florida-Friendly plants, we have created a website with all the plants in our demonstration gardens.
The site is organized by garden area, common name, and botanical name to ease navigation. Each plant profile has photos at different stages, basic cultural information, and links to additional research-based information.
Whether you are visiting our gardens in person or just want information on plants that perform well in the Florida Panhandle, we hope you will check out our new site and let us know if you found it useful and how we can improve.
Pollinator hotel. J. McConnell, UFIFASGinkgo leaves. J. McConnell, UFIFASBlanket flower. J. McConnell, UFIFASAmerican beautyberry. J. McConnell, UFIFASEastern redbud. J. McConnell, UFIFASPollinator garden. J. McConnell, UFIFASMaypop flower. J. McConnell, UFIFASAutumn fern. J. McConnell, UFIFASHummingbird at red bottlebrush flower. J. McConnell, UFIFAS
October is an important month for butterflies. The monarchs are making their epic migration towards Mexico, gracing us with their presence as they stop to feed on saltbush or lantana plants along the coast. But our homegrown orange-and-black butterfly is showing up everywhere right now, too. The Gulf fritillary (Agrautis vanillae) is a smaller species, but also features bright orange wings with black stripes and spots. Their caterpillars come dressed for Halloween, too—they are a deep orange color with black legs and spikes. While the caterpillar is not venomous to any potential predators, the spikes are quite intimidating and serve a protective function.
A gulf fritillary butterfly gathering nectar from a similarly brilliant orange flower. Photo credit: Carrie Stevenson, UF IFAS Extension
Fritillary (name from the Latin “chessboard”) eggs are bright yellow and laid primarily on varieties of passionflower vines, which the caterpillars feed voraciously upon. Passion vine is an important host plant for the zebra longwing as well, which is Florida’s state butterfly.
Gulf fritillaries are found in all 67 Florida counties, and may live throughout the southeastern United States, Mexico, and central and south America. They are found in varied habitats but prefer open, sunny spots in fields, forests, and gardens. The butterfly’s wing shape puts them into the “longwing” category, as their elongated wings spread wider than other species.
Caterpillar of the Gulf fritillary butterfly on corkystem passionflower. Photo credit: Jaret C. Daniels, University of Florida.
In the fall, fritillaries migrate to the warmest ends of their range. By spring, they move slightly north into North Carolina or interior Alabama.
