Landscape Lessons from Recent Freezes

Landscape Lessons from Recent Freezes

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.

Autumn Brings Changes in our Landscapes

Autumn Brings Changes in our Landscapes

The shorter days and cooler temperatures of autumn bring on changes in our shrubs and trees.

Most people expect to see changes in leaf color in deciduous trees and shrubs during fall. But some people become concerned when the leaves on certain evergreen plants begin to turn yellow with the change in the seasons. For many plants this is normal.

Azaleas may lose a few leaves now. These are the older leaves on the branches near the center of the plant. There is no need for alarm by the loss of a few older azalea leaves from now until spring. However, if the younger leaves, those nearest the tip of the shoot, turn yellow or brown there is cause for concern. Poor drainage, lack of water or alkaline soils may cause this condition. Be sure to keep azaleas and other ornamental plants well-watered during dry weather that may occur from now through spring.

Other plants such as gardenias, hollies and camellias may have yellowing leaves now. But as with azaleas, these are the older leaves on the stem near the center of the plant. The mature leaves will drop from the plant from now until spring. This is only the normal aging of older leaves. However, be careful to not confuse this normal process with spider mites, scale, lace bugs, nutrient deficiencies, poor growing conditions or salt injury. Just keep in mind that this normal change in leaf color and leaf drop occurs on the older leaves generally during cooler weather – it’s a seasonal change.

Young red maple with fall foliage. Photo credit: Larry Williams

The leaves of sycamore trees have changed from green to brown by now. Although the sycamore is a deciduous tree, this phenomenon may not be caused by a change in day length or temperature alone. This change in leaf color in sycamores can begin in late summer. Many times, it is the result of sycamore lace bugs feeding on the leaves. By the time the damage is visible, there is little that can be done to correct the problem. However, this problem will take care of itself since sycamore trees will soon be dropping their leaves.

We do have some trees that exhibit beautiful fall foliage this time of year. A few to consider include hickory and gingko for their bright yellow fall foliage, black gum for its early display of brilliant red, purple or orange leaves and Chinese pistache for its late reddish-orange fall show. There are plenty of other good trees to consider for fall color here in North Florida such as dogwood, crape myrtle, Florida maple, sourwood, shumard oak and the list could continue.

Select and Plant Trees for Florida’s High Wind Climate

Select and Plant Trees for Florida’s High Wind Climate

Many future problems can be avoided by paying attention to tree selection, planting and maintenance in Florida’s high wind climate. We may think of tropical storms causing tree damage but our typical summer thunderstorms can produce winds in excess of 50 miles per hour with downbursts reaching over 100 mph. 

There is no way to protect trees from all storm damage. Trees are not adapted to worst-case storms, such as Hurricanes Michael or Ian, only to our average wind climate.

It’s wise to take time to select and correctly plant the right trees for North Florida.

Past hurricanes have taught us that large growing trees planted too close to curbs, sidewalks or buildings blow over easily because they don’t have adequate room to develop a sound root system. It’s best to either plant these trees farther away, plant trees that may stay small, or increase the size of space allocated for tree root growth.

Research and storms have taught us that tree roots need large soil spaces for strong, stable growth. The more rooting space trees have, the less likely they are to fail. Strong root growth is essential for tree stability and health. Large maturing trees need at least 30 feet by 30 feet (900 ft. sq.) of rooting space. Many construction practices such as paving over roots, raising and lowering soil grade, and soil compaction from equipment result in root injury for existing trees, making them less durable and less stable.

Magnolia Tree in the Landscape. Photo courtesy Stephen Greer

Studies have also shown that trees growing in groups better survive high winds compared to individual trees. A group was defined as five or more trees growing within ten feet of another tree, but not in a row.

A short list of large maturing, storm resistant trees to consider include live oak, sand live oak, bald cypress, pond cypress, black gum and magnolia.

Do some homework and take a look at tree species that have done well in your area. If you don’t want or need a large tree in your yard, there are many small and medium sized wind-resistant trees from which to choose, like Crape Myrtle and Vitex. Many palms are wind resistant too, particularly the cabbage palm.

Having success with trees in the landscape involves starting with healthy, well-developed trees. Plant the right tree in the right place. Follow good planting procedures, including not planting trees too deep and providing adequate root space to allow for strong, healthy root growth. Practice correct maintenance techniques, which includes learning how to prune to produce a structurally sound tree. Finally, consider if it is time to be proactive and have large over-mature, declining trees removed and replaced before the next storm.

The following UF/IFAS Extension link, Trees and Hurricanes, includes the most current recommendations on tree selection, planting and pruning. https://hort.ifas.ufl.edu/treesandhurricanes/wind_and_trees.shtml

Reduce Gasoline Use in Your Yard

Reduce Gasoline Use in Your Yard

UF/IFAS Extension Turfgrass Researcher Dr. Bryan Unruh with robotic mower

Dr. Bryan Unruh with robotic mower. Credit: UF/IFAS

With gas prices increasing, there are practical ways to reduce gasoline use in your own backyard.

There are electric, battery, solar powered and robotic (autonomous) lawnmowers. Do you remember the non-motorized reel mower? Or, you could use sheep. But, for the time being, most people have gasoline powered mowers.  There are costs involved with mowing, including the cost of gas or diesel fuel.

Be smart as to where you grow grass. Use grass where it serves a purpose. Concentrate your efforts in growing grass where it will grow. It’s normal for lawns to decline in close proximity to large trees. As a lawn gives way to tree competition, do something else in that area. Use mulch under trees or plant shade tolerant plants.

Fertilize smart. Lawns need fertilizer. But, too much fertilizer, particularly too much nitrogen, results in excessive grass growth that requires more mowing.

Many homeowners overdo it with too much nitrogen and too little potassium. Fertilizers with the correct ratios of nitrogen to potassium will produce the right balance of shoot to root growth. Choose a fertilizer such as 15-0-15 or some similar analysis with some slow release nitrogen. Fertilize to produce adequate growth and the correct color. If your lawn is a healthy green and you’re mowing, mowing, mowing… why add more fertilizer?

Centipedegrass and bahiagrass will grow best with fewer problems when fertilized sparingly. This would be one or two light applications of fertilizer per year, or none at all if these grasses are performing well. St. Augustinegrass and zoysiagrass might get by on one spring application; however, it’s more common to apply a second time during summer.

Never apply more than the recommended amount of fertilizer per application.  You can always split the total amount into two or more applications, which will produce more even growth and minimize sudden growth spurts.

Though it’s a popular practice, reconsider overseeding your lawn with ryegrass this fall. Weigh the desire to have a green lawn through winter with the extra time and costs (gas, fertilizer, water and pesticides) involved with maintaining it.

Finally, keep your gas-powered lawnmower in good working condition. It can make a difference in how efficiently it operates. Make sure the equipment is clean. Change the oil if needed. Replace or clean the air filter and spark plug. Keep lawnmower blades sharp. Basically, follow the owner’s manual for routine maintenance.

Implementing these ideas can help conserve fuel and result in a healthier lawn.

Method for Trapping Pesky Deer Fly

Method for Trapping Pesky Deer Fly

Deer fly trap as created by Dr. Russ Mizell

Deer fly trap. Photo credit: Russ Mizell

Recently, I’ve been asked about a deer fly trapping method that I wrote about a number of years ago. So, here it is. This aggravating insect is active now.

Deer flies, which are in the horsefly family, are annoying as they repeatedly and persistently dive for their victims until they inflict a painful bite.

Dr. Russ Mizell, now retired UF/IFAS Extension entomologist, experimented with a method to trap this insect. Mizell wanted to identify the optimum shape, size, color and speed to attract deer flies. If successful, he could temporarily remove a deer fly population long enough to enjoy an outdoor gathering without being bothered by deer flies.

Mizell said he started the research as a high school science project with his son but “it got so interesting, I just kept doing it.”

Deer flies wait for prey to walk before attacking. So, they are highly attracted to movement.

With this in mind, Mizell and his son decided the best way to snare deer flies was to “troll” for them from a slow-moving vehicle. Working in spring and summer when deer flies are most prominent, they set out to discover what kind of trap worked best.

They built a test platform on the hood of their vehicle that could troll seven different shapes at once. They ambled along in deer fly-infested countryside for set periods of one to five minutes, testing pyramids, squares, balloons, plant containers and other shapes, all coated with Tanglefoot (commercially available sticky spray for insects), then counting immobilized prey. They tried black, tan, blue and shapes of other colors suspended from various heights.

The trap that enticed the most deer flies proved to be a 6-inch flowerpot painted bright blue and coated with Tanglefoot. This trap captured as many as 30 deer flies in a one-minute test. It worked best when suspended three to six feet above the ground and trolled no faster than 10 feet per second or about 7 miles per hour.

The traps are remarkably effective, Mizell said. “Many times, after running the traps through an area, we found there were no deer flies left,” he said. “You trap them out for a short period until they repopulate the area.”

The traps also work when attached to a baseball cap and trolled by the hat’s wearer. But instead of attaching a flowerpot to your cap, you could attach a blue drink cup painted with Tanglefoot.

Despite its effectiveness, its aesthetic appeal leaves something to be desired.

For more information including instructions and pictures of how to make a deer fly trap visit the below site. http://entomology.ifas.ufl.edu/pestalert/deerfly.htm