Why Don’t We Get Great Fall Color in Florida?

Why Don’t We Get Great Fall Color in Florida?

red fall color on a tree

Intense red fall color of Japanese Maple in Georgia is hard to replicate in our climate. J_McConnell, UF/IFAS

Fall is a favorite time of year for many people. Cool nights, short days, football games and the fast approaching holidays are all signs of summer coming to an end. Floridians who have relocated from other parts of the country may be disappointed to realize we get very little showy fall color even though we can grow some of the same trees in North Florida as other parts of the country. Why is that? Well, although plant breeders may promise “showy fall color” in certain selections, they really can’t promise that year after year because it’s more than just genetics influencing leaf color. Let’s take a deeper dive into the science behind fall color!

Why do the leaves change color?
Lower temperatures and shorter day length indicate to plants that winter is approaching and some physiological changes start to occur. Chlorophyll is a pigment found in leaves that, in addition to capturing sunlight and producing energy, also causes plants to display green during the growing season. As fall approaches, environmental changes tell plants to stop producing chlorophyll and existing pigment begins to break down. The reduction of chlorophyll allows the other pigments present (carotenoids and anthocyanin) to reveal their colors in an array of yellows, browns, oranges, reds, and purples. Different plants have different levels of these pigments and some may not exist at all in certain species. This explains why some plants typically turn only yellow and others may show yellow, orange, and/or red!

Why is there so much difference from year to year?

Variation occurs because environmental conditions and cultural practices play a part in determining how much color will be on display. Rainfall or irrigation amounts in the preceding summer and fall, drought cycles, nutrient levels, sunlight, and day and night temperatures all influence color from year to year.

How do I increase the potential for showy fall color in my landscape?

Choose plants with the reputation of producing desired fall colors in our area. However, keep in mind that because of the influence of outside conditions, you may be in for a surprise from year to year. To increase your chance of having a somewhat predictable fall display, use cultivars instead of seedlings of a plant species. A cultivar is a selection of a plant species that has been chosen for desirable traits, like growth habit, flowering, or fall color.  These attributes are usually easily identified by the way their names are assigned. For example, Acer rubrum ‘October Glory’ is a red maple cultivar known for a full rounded canopy and exceptional red fall color. The reason that cultivars appear more consistent is because they are genetic copies of the parent plant that they are named for. A species or seedling plant is not a clone but comes from seed, which means you will get as much genetic variation as you see in human siblings. Just like children in our own families, each will each shine in their own way and no two will be exactly alike. 

Meet the Author Julie McConnell

Meet the Author Julie McConnell

Julie McConnell with moose in background.

Stopped for a photo with a moose in Allenspark, Colorado this summer.

Julie McConnell is the Horticulture Agent with UF/IFAS Extension Bay County. She was hired in 2012 with a Bachelor of Science in Ornamental Horticulture from Auburn University, but the position also required a master’s degree. From 2014-2016 Julie attended the University of Florida’s distance learning program to earn a Master of Science in Entomology and Nematology and a Graduate Certificate in Landscape Pest Management. Although it was challenging to juggle family, work, and classes she quickly found that insects are fascinating creatures and the knowledge she was gaining could be applied daily on the job.

An Army brat, Julie lived all over the Southeast and in Hawaii before her parents settled in South Florida where she spent most of her childhood. Growing up she had no interest in plants or insects but loved animals and hoped to one day be a veterinarian. Fast forward many years to a few failed physics and chemistry classes triggering undergraduate major changes and eventually Julie found a good fit with Horticulture while studying at Auburn. She flourished in that program and found a job in wholesale nursery sales in the metro-Atlanta market upon graduation in 2001.

While working on her degree at Auburn, Julie worked as a Public Safety Communications Officer with the City of Auburn for 6 years. In that role she helped write standard operating procedures and a formalized training program and trained new hires. She also served 8 years in the U.S. Army Reserves at an Aviation Headquarters Unit at Ft. Rucker, Alabama.

Julie has been married for 15 years and has 4 children and 3 grandchildren. She lives in northern Bay County with her husband and their youngest child. They love spending time in or on the water and have picked up new hobbies including kayaking and diving since moving to Florida. They also enjoy traveling and hosting family and friends visiting from out of state. In addition to sharing the beautiful beaches of Bay County, they like to introduce visitors to other outdoor recreational spots such as the crystal-clear springs and dune lakes in Northwest Florida.

kayaking in Florida

Although I never catch any fish, I love family time on the water.

Bill and Julie McConnell diving at St. Andrews State Park. 2019

Bill and Julie McConnell diving at St. Andrews State Park. 2019

Making Effective Herbicide Selections

Making Effective Herbicide Selections

BooksEarlier this summer I talked about getting to know your weeds, so they’ll be easier to control. If you missed that article you can review it here “Why Can’t I Kill Weeds?”

Today we will look at the types of herbicides available so your selection will fit your situation.

Understand your herbicide options. Picking out the appropriate herbicide can be overwhelming. The options seem unlimited when you are standing in the store looking at aisles of containers. By preparing yourself before you shop you can save time and increase your chances of making the most effective selection. Here are some herbicide basics:

  • Label interpretation. The pesticide label is a multipage document that describes ingredients, how a pesticide works, application instructions, safety requirements, and other important information for the user. Before applying any pesticide (yes, herbicides are pesticides!) you should read the entire label. Pulling the label off the package in the store may be frowned upon and the print is very small. For this reason, I would recommend looking up a few options before you go shopping and reading the labels online. This allows you to take your time to be sure you understand if it is the appropriate product and you can make your shopping list for personal protective and application equipment before you leave the house. Three important things to look for when selecting your product are active ingredient, labeled site (site includes the location such as residential landscape vs. agricultural crops and the plants it is safe to use on), and targeted pest.
  • Grass showing reaction to herbicide

    Non-selective, systemic herbicide damage on grass. Photo: J_McConnell, UF/IFAS

    Pre-emergent herbicides. Pre-emergent herbicides provide control when applied BEFORE seed germination of your target weed. They do not prevent germination, rather they prevent emergence of shoots and roots essentially inhibiting normal plant growth which eventually results in plant death. It is important to have your product in place during the correct window of time. Typically, 1-2 weeks before germination of your target weed is ideal.

    • For warm season annual weeds (crabgrass, goosegrass, sandspur, and spurge are examples) apply pre-emergent herbicides when day temperatures in early spring reach 65-70°F for 4-5 consecutive days. This may be mid-February or as early as January.
    • For winter annual weeds (henbit, black medic, geranium, and chickweed are examples) watch for night temperatures in the Fall to reach 55-60°F for several nights in a row to indicate proper application timing.
    • Some products are selective to plant types such as grasses, sedges or broadleaf weeds. Other products are more broad-spectrum and are effective on multiple weed types.
    • Pre-emergent herbicide should not be used if you intend to plant seed – it will affect your desired plant in addition to the weed! There may also be effects on newly planted lawns or plants, so be sure to read the label closely to avoid damage to non-target plants.
  • Post-emergent herbicides. These products are used on weeds that have already emerged, regardless of life cycle (annual, perennial, biennial). This type of herbicide will be applied directly to the weed you are trying to kill. There are a few categories within this group.
    • Selective or non-selective.
      Selective herbicides work on particular categories of plants: broadleaf, sedge, grass, or woody plant.
      Non-selective herbicides can kill any type of plant regardless of category.
    • Contact or systemic.
      Contact herbicides kill the plant tissue it comes into contact with and does not translocate to the rest of the plant.
      Systemic herbicides are translocated throughout the plant to affect more than just the place of absorption. These are ideal for perennial weeds that would regenerate from roots, bulbs, or tubers if the top is damaged or killed.

Effective weed management requires some preparation and research for the best outcome. For help with weed identification and control recommendations, contact your local UF/IFAS Extension Office.

Further reading on weeds and herbicides:
Florida Homeowner Herbicide Guide: Considerations, Applications, and Selection 
Postemergent Herbicides for Use in Ornamentals
Weed Management Guide for Florida Lawns

Butterfly Gardening Resources

Butterfly Gardening Resources

We hope you were able to join us for Gardening in the Panhandle LIVE! Butterfly Gardening on July 9th to learn about attracting butterflies to your Florida gardens. As promised, we have compiled a list of butterfly resources that we talked about during the webinar and a few extra that we didn’t have time to cover.

If you were not able to join us live, you can still watch the videos on Facebook or YouTube

Click on the topic of interest for links to resources:

Don’t forget to tune in for our next Gardening in the Panhandle LIVE! on July 23rd for Prepping for the Fall Garden. Register for that webinar on Zoom or Follow our Facebook Event for updates.

For a full list of upcoming webinars visit Gardening in the Panhandle: LIVE!
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Why Can’t I Kill Weeds?

Why Can’t I Kill Weeds?

Why are the plants we are trying not to grow so hard to kill? Weeds can be quite frustrating to home gardeners as they struggle to get them under control. There are a few things you can do to help make your efforts more successful.

Identify the weed. It might seem like it doesn’t matter what the plant is if you know you want to get rid of it, but a big part of your strategy should be figuring out why that plant is being so difficult. Below are the reasons why weed identification is so critical in your fight to control it.

  • Which plant are you favoring with your maintenance routine? All plants have similar basic needs: water, sunlight, nutrients, and a space to grow, but some perform better with varying amounts of each of these inputs. Sometimes we can influence these factors in a way that favors one plant over another. The best example is how we irrigate our landscape. If you plant drought tolerant shrubs, such as Indian Hawthorne, which can survive with little to no irrigation after establishment, and then continue to water 2-3 times a week, is it any wonder that you get water loving weeds such as dollarweed, torpedograss, or sedge? Only apply inputs that support your desirable plants and nothing more.
  • Recognize the weed type. There are three main types of weeds we typically encounter: broadleaf, grass, or sedge. Some herbicides are broad-spectrum, which means they kill any type of plant, while others are selective. Selective herbicides generally target either broadleaf, grass or sedge weeds and have minimal impact on the other types. This can be very important information to have if you are shopping for an herbicide.
  • Understand the life cycle. Herbaceous plants fall into three main life cycle categories: annual, perennial, or biennial. Annuals and biennials tend to reproduce primarily from seed. The annual plant completes its entire life cycle in one season or year and a biennial takes two years. When targeting these two, your goal is to get rid of the plant before it flowers and sets seed to reduce future crops. If you miss that window and the weeds go to seed, plan to use a pre-emergent herbicide prior to their next scheduled germination date (usually the next season). Perennials live for more than 2 years and tend to be tough to manage. They may reproduce by seed but many also multiply by vegetative means. To put this simply, they store everything they need in tiny pieces of the plant and if left in place, it will generate more plants. So, that little tiny root fragment from dollar weed you didn’t pull up – yep, it’ll grow a whole new one in its place!

For more information on weeds and weed control in lawns and landscapes, contact your local UF/IFAS County Extension Office!