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Arbor Day: An American-born Celebration

Arbor Day: An American-born Celebration

Arbor Day has a 145-year history, started in Nebraska by a nature-loving newspaper editor named J. Sterling Morton who recognized the many valuable services trees provide. The first Arbor Day was such a big success that Mr. Morton’s idea quickly spread nationwide–particularly with children planting trees on school grounds and caring for them throughout the year. Now, Arbor Day is celebrated around the world in more than 30 countries, including every continent but Antarctica. We humans often form emotional attachments to trees, planting them at the beginning of a marriage, birth of a child, or death of a loved one. Trees have tremendous symbolic value within cultures and religions worldwide, so it only makes sense that people around the world have embraced the idea of celebrating a holiday focused solely on trees.

Ancient trees like this live oak have an important place in our cultural history. Photo credit: Carrie Stevenson

In addition to their aesthetic beauty and valuable shade in the hot summers, trees provide countless benefits: wood and paper products, nut and fruit production, wildlife habitat, stormwater uptake, soil stabilization, carbon dioxide intake, and oxygen production.  New research is even showing that trees can communicate throughout a forest, sharing “information” and nutrients through a deeply connected network of roots and fungi that can increase the resiliency of an entire forest population. And if you’re curious of the actual dollar value of a single tree, the handy online calculator at TreeBenefits.com can give you an approximate lifetime value of a one growing in your own backyard.

While national Arbor Day is held the last Friday in April, Arbor Day in Florida is always the third Friday of January. Due to our geographical location further south than most of the country, our primary planting season is during our relatively mild winters. Trees have the opportunity during cooler months to establish roots without the high demands of the warm growing season in spring and summer.

To commemorate Arbor Day, many local communities will host tree giveaways, plantings, and public ceremonies. In the western Panhandle, the Florida Forest Service, UF/IFAS Extension, and local municipalities have partnered for several events, listed here. As the Chinese proverb goes, “The best time to plant a tree was twenty years ago. The second best time is now.”

For more information on local Arbor Day events and tree giveaways in your area, contact your local Extension Office or County Forester!

 

American Beech–an American Beauty

American Beech–an American Beauty

During a recent hike through wooded property in Walton County, our Florida Master Naturalist class came across a stunning example of an American Beech tree (Fagus grandifolia). As we looked closely at its thick, sinewy trunk (often compared to an elephant’s skin), the bark changed hues from a deep red to silvery gray and brown. A hardwood, it has been used over the years to make furniture, railroad ties, and beer barrels. Like many of the local hardwood species, beech wood holds up to decay when exposed to water and early settlers used it to build mills and water wheels.

The colorful, smooth bark of a beech tree is eye-catching and strong. Photo credit: Carrie Stevenson

The colorful, smooth bark of a beech tree is eye-catching and strong. Photo credit: Carrie Stevenson

During the growing season, the beech tree can be identified by its distinctive dark green, tooth-edged leaves. Beeches are deciduous but have the unique quality of usually keeping dead leaves on their branches all winter, which also helps with identification in the forest.

The most fascinating observation, to me, was the series of tightly swirled branch buds ready to sprout at the tips of each new branch. So pointed that they’re easily confused as thorns, these long protrusions will eventually grow into new branches.

These four buds formed as an "emergency" response to the branch being cut and will eventually replace it. Photo credit: Carrie Stevenson

These four buds formed as an “emergency” response to the branch being cut and will eventually replace it. Photo credit: Carrie Stevenson

At the end of one branch that had been cut, the tree’s internal “emergency response” system formed four new immature branches, which had the intimidating appearance of a claw. Eventually, one of these buds will outcompete the others and grow into a new branch.

Beeches are of course known for the beech nut, eaten by humans and wildlife alike. If you’re considering a beech for a home landscape, be sure you have a wide open space with moist soil, as a mature beech can grow up to 75 feet high and 40-60 feet wide. Its low branches create a lot of shade, so understory plants are usually unnecessary or even impossible to grow.

For more information on these interesting native trees and others like it, contact your local UF IFAS Extension Office or visit the UF Landscape Horticulture page.

Helping Turfgrass Overcome Herbicide Injury

Helping Turfgrass Overcome Herbicide Injury

Dr. Ramon Leon, Extension Weed Specialist, West Florida Research and Education Center

Herbicides simplify weed management by allowing you to cover extensive areas in a relatively short time, and reduce the need for time-consuming control practices such as hand weeding. Additionally, many herbicides have the advantage of selective control. Selective herbicides are those that kill weeds without significantly injuring the desired plant. In turfgrass, selective herbicides are particularly important because we do not have the option of using cultivation or non-selective herbicides, as is commonly done in other agricultural systems such as row crops and orchards.

A common misconception is that when a herbicide is registered for use on a given turfgrass species, this herbicide has little negative effect on the turf. In reality, even when the herbicide is registered for a specific turfgrass species, it can cause a certain level of injury. If the herbicide is applied at the recommended label rate, and the growing conditions are ideal, the turfgrass will only suffer minor, temporary injury that may go completely unnoticed. Conversely, the weeds that are susceptible to the herbicide will be severely affected resulting in the desired control.

Over the last few summers, there has been an increase in complaints about herbicide injury on sod farms, golf courses, and home lawns after applications of herbicides, especially during the summer months. Many of those complaints originated from situations in which the application was done properly, using the recommended label rate, and thus the level of injury observed was not justified. After studying all these cases, it was determined that at the time of herbicide application the turf was under a moderate level of stress, but not high enough stress to cause visible symptoms. However, when the herbicide was applied the combined effect of the existing stress, and the stress caused by the herbicide made it harder for the turf to maintain the desired quality. For example, Figure 1 below shows that the turf looked fine before the application (A), but after the herbicide was applied, there was a significant loss in turf cover and quality (B). The interesting aspect is that the injury was not present across the entire treated area, but only on patches (C). Those patches corresponded with sand pockets where soil moisture, especially on hot days, was considerably lower than the rest of the area. In that particular case, the irrigation system was providing enough water to help the turf tolerate the moderate stress of high temperatures and limited moisture, but not enough for the turf tolerate the combined stress that occurred after the herbicide was applied.

Figure 1. Centipedegrass growing during the summer in Florida before herbicide application (A), 3 weeks after herbicide (sulfentrazone and metsulfuron-methyl) application (B). Herbicide injury pattern with highlighted areas showing where sand pockets caused drought and heat stress that contributed to herbicide injury (C).

Figure 1. Centipedegrass growing during the summer in Florida before herbicide application (A), 3 weeks after herbicide (sulfentrazone and metsulfuron-methyl) application (B). Herbicide injury pattern with highlighted areas showing where sand pockets caused drought and heat stress that contributed to herbicide injury (C).

 

In Florida, there are a combination of environmental factors such as high temperatures and sandy soils that can create stressful conditions limiting turfgrass growth, especially when irrigation is not sufficient to keep the turf hydrated.  Furthermore, we also experience periods of excess rainfall, and areas of turf growing under shade. Additionally, pest problems that affect roots and leaves are frequently found in our state. All these conditions affect turfgrass health and its ability to tolerate herbicide applications. For these reasons, turf producers and managers need to be proactive to help turfgrass overcome the injury that herbicides might cause. To achieve this goal, you need to follow five simple steps:

1) Identify weed problems early. Most weed problems will start in the spring for summer weeds and in the fall for winter weeds. Controlling them when they are small not only increases the effectiveness of our applications, but also allows us to implement our control when the turfgrass is less likely to be stressed.

If herbicide applications are needed when conditions might be stressful for the turf (high temperatures and/or dry conditions)

2) Make sure irrigation is adequate (increase frequency or duration if needed) for up to three weeks following application.

3) Reduce mowing frequency and increase mowing height 0.5 inches for up to 3 weeks following a herbicide application, to allow the turfgrass to continue producing energy to support its recovery. Mowing too short and too frequently immediately after the application weakens the turfgrass.

4) Fertilize with a small amount of nitrogen (0.25 to 0.5 lb N/acre) a week or two after herbicide application to help the turf recover and produce new leaves.

5) If the turfgrass is suffering from serious pest problems (pathogens, nematodes or insect infestations) do not apply herbicides on the affected areas until the turfgrass has recovered.

Maintaining optimal turfgrass growth is the best way to ensure that herbicide applications will maximize weed control while still protecting the health and aesthetics of your turfgrass.

For more information on growing turfgrass in Florida, please see the following:

Florida Lawn Handbook

 

 

Dr. Ramon Leon, Extension Weed Specialist, West Florida Research and Education Center

 

Saltbush–a Native Beauty, of Sorts

Saltbush–a Native Beauty, of Sorts

Saltbush seed in "bloom" stands out in a saltmarsh dominated by black needlerush. Photo credit: Zach Schang, FDEP

Saltbush seed in “bloom” stands out in a salt marsh dominated by black needlerush. Photo credit: Zach Schang, FDEP

In the spring and summer, no one notices the little green shrub hidden among wax myrtle and marsh elder at the edge of the salt marsh. However, if I’m leading a group of students or a Master Naturalist class through the same area in the fall, it’s the first plant people ask about. The saltbush or groundsel tree (Baccharis halmifolia) blooms dramatically in late September and October, with feathery, dandelion-like white “flowers” on female plants. These seeds are dispersed far and wide by the wind. Male plants typically grow side-by-side with females, and produce yellowish, tubular blooms at the same time. Characterized as both a large shrub and a small tree, the saltbush typically branches from multiple trunks and ranges in height from 2-10 feet. The leaves are rough to the touch and slightly succulent, enabling the plant to hold onto moisture in the sandy, hot environments on the  uphill edges of wetlands in which it thrives.

The leaf of Baccharis angustifolia is narrower than B. halmifolia. Both are succulent, enabling the plants to hold on to moisture in a salty environment. Photo courtesy Shirley Denton, Florida Plant Atlas.

The leaf of Baccharis angustifolia is narrower than B. halmifolia. Both are succulent, enabling the plants to hold on to moisture in a salty environment. Photo courtesy Shirley Denton, Florida Plant Atlas.

The leaf of Baccharis halmifolia is lobed and wider than B. angustifolia is narrower. Both are succulent, enabling the plants to hold on to moisture in a salty environment. Photo courtesy Forestry Images.

The leaf of Baccharis halmifolia is lobed and wider than B. angustifolia is narrower. Both are succulent, enabling the plants to hold on to moisture in a salty environment. Photo courtesy Forestry Images.

The plant is often confused with its near relative, false willow (Baccharis angustifolia), which is typically co-located with saltbush in coastal wetlands. It also blooms white in the fall, but can be differentiated by its slender, almost needle-like (but also succulent) leaves.

Saltbush is not typically used in the home landscape, as some people are allergic and the seeds are poisonous if ingested. Properly planted, however, it is a perfect addition to a butterfly garden because the male plants’ fall flowers provide nectar to numerous butterfly species, including the monarch. Another ideal location for saltbush would be a rain garden or the edges of a stormwater pond. Coastal property owners on the bay or Gulf would find it an excellent addition due to its tolerance of the year-round salt spray. The species is very hardy–tolerant of both wet and dry soils–along with a variety of soil pH levels. Plant saltbush in full sun with at least 3-5 feet between young plants.

For additional information on the characteristics of saltbush, please see the UF publication, Baccharis halmifolia Saltbush, Groundsel Bush and check out this entertaining video from our Lee County colleague, Stephen Brown, as he immerses himself in a stand of saltbush.

 

The Fig

The Fig

Summer is full of simple pleasures—afternoon rainstorms, living in flip flops, and cooling off in a backyard pool. Among these, one of my favorites is walking out my door and picking handfuls of figs right from the tree. Before we planted our tree, my only prior experience with the fruit was a Fig Newton—I’d never eaten an actual fig, much less one picked fresh. Now, they are my favorite fruit.

Ripe figs are a deep shade of pink to purple. Larger green figs will ripen in a few days. Photo credit: Carrie Stevenson

When ripe, figs are a deep shade of pink to purple. Larger green figs will ripen over the course of a few days. Photo credit: Carrie Stevenson

Native to Asia Minor and the Mediterranean, figs were introduced to Florida in the 1500’s by Spanish explorers. Spanish missionaries introduced these relatives of the mulberry to California a couple hundred years later. Figs are best suited to dry, Mediterranean-type climates, but do quite well in the southeast. Due to our humidity, southern-growing figs are typically fleshier and can split when heavy rains come through. The biggest threats to the health of the trees are insects, disease (also due to our more humid climate) and root-knot nematodes.

Fig trees can grow quite large and produce hundreds of fruit each year. Photo credit: Carrie Stevenson

Fig trees can grow quite large and produce hundreds of fruit each year. Photo credit: Carrie Stevenson

Our tree started out just a couple of feet tall, but 12 years ago we replanted it along a fence in our back yard. It has grown so large (easily 25 feet tall and equally wide) that it hangs over our driveway, making it handy to grab a few as I hop in the car to run errands. The tree is in full sun at the bottom of a slope, and seems to be a satisfied recipient of all the runoff from our backyard. This position has resulted in a thick layer of soil and mulch in which it thrives.

We usually see small green fruit start to appear in early May, becoming fat and ripe by the second half of June. The tree produces steadily through early August, when the tree’s leaves turn crispy from the summer heat and there’s no more fruit to bear. The common fig doesn’t require a pollinator, so only one tree is necessary for production. The fiber-rich fig is also full of calcium, potassium, and vitamins A, E, and K. As it turns out, the “fruit” is actually a hollow peduncle (stem) that grows fleshy, forming a structure called a synconium. The synconium is full of unfertilized ovaries, making a fig a container that holds both tiny flowers and fruit in one.

The insides of a fig show the small flowering structures that form the larger fruit. Photo credit: Carrie Stevenson

The insides of a fig show the small flowering structures that form the larger fruit. Photo credit: Carrie Stevenson

With the hundreds of figs we’ve picked, my family has made fig preserves, fig ice cream, baked figs and of course eaten them raw. We typically beg friends and neighbors to come help themselves—and bring a ladder—because we can’t keep up with the productivity. Often you can tell you’re near our tree from around the block, as the aroma of fermenting fruit baking on the driveway is far-reaching.

No matter what you do with them, I encourage planting these trees in your own yard to take full advantage of their sweet, healthy fruit and sprawling shade. As Bill Finch of the Mobile (AL) botanical gardens has written, “fresh…figs are fully enjoyed only by the family that grows them, and the very best figs are inevitably consumed by the person who picks them.”