by Ian Stone | Nov 21, 2024
Not all trees and woody species are welcome in the landscape. In fact, some woody species can be pesky and problematic and for lack of a better term “weeds”. Despite the fact that some of these species are native trees, bushes, and vines, many can be aggressive and problematic in the home landscape and urban settings. If you have ever cared for a flower bed or garden in the Panhandle, you are probably well acquainted with these and have pulled seedlings and small saplings out of beds, hedges, and seemingly any other nook and cranny of your landscape. If you cut them off using loppers or a saw you also know how aggressively they resprout and how extensive their root system can become. Vegetation grows quickly and often aggressively in our humid sub-tropical climates. If you leave an area of land vacant for very long here, it quickly becomes a thicket in no time. Some of our oaks, particularly water and laurel oaks, can be pesky and troublesome. It seems like I am constantly battling problem oaks in my home landscape, with varying degrees of success. I will pull out, cut out, and apply herbicide only to look up and see a substantial oak sapling rocketing up through azaleas or other hedges. Without fail this is a water or laurel oak nearly 100% of the time, with some other hardwood trees and shrub species thrown in occasionally.
Oak sapling overtaking shrubbery in a local landscape Escambia County, FL Photo Credit: Ian Stone
What is the best way to tackle these pesky woody “weeds” when they cause persistent problems and pop up in undesirable spaces? The answer is to either mechanically removal them or employ very careful and targeted herbicide application. As a professional forester I have spent a large part of my career controlling these brush species using a host of mechanical and herbicide control methods and very well planned prescribed fires. Obviously using large heavy machinery and prescribed fire in urban and suburban settings and landscapes is not an option but using hand tools for mechanical removal and herbicides where needed and best suited is a winning combo for the home landscape.
First you want to determine what species you are dealing with and what stage of development it is in. As I mentioned, water oak and laurel oak are usually the problem oaks we encounter and can reproduce at extremely high rates and create undesirable crowded stands of stunted oak. These species are what foresters call early successional, meaning they tend to establish in forest openings and areas impacted by a disturbance such as a hurricane or windstorm. They produce large amounts of small acorns and grow very fast and they also have poor characteristics where they are susceptible to wind throw and disease. Effectively, they reproduce heavily, grow fast, and die young; that is their natural adaptation and life cycle and what causes them to be pesky and weedy in the home landscape. We don’t realize it, but our home lawns and flower beds create the perfect early successional habitat for these oaks and other brush species such as yaupon holly, titi, wax myrtle, and others. It doesn’t stop there – in heavily shaded areas, very shade tolerant oaks, brush, and vines tend to become established. Vines such as Virginia creeper, greenbriers (Smilax spp.), pepper-vine, and others are particularly annoying as these woody species also love to grow up in fences, particularly chain link, and are difficult to remove.
So what are the best methods to handle problem woody species in the home landscape? The best option is to catch them as seedlings and young plants and pull them up by the roots and all. If you can do this, you will avoid issues with resprouting. If you have larger, more well-established brush and small trees in your landscape, you can cut them back close to the ground, but you are likely to have issues with resprouting. This can be very frustrating and can result in a persistent problem. By consistently cutting these back you may be able to exhaust the plant’s reserve, but this is unlikely. Depending on the size of the root system you may be able to dig up the roots using some elbow grease and a shovel or mattock, but if significant roots are left behind, some woody species can resprout from the remaining roots. This is when simply cutting off the main stem or other mechanical methods often are not sufficient for long term control.
When dealing with well-established woody species with a significant stem size, using a properly labeled and effective herbicide can be a big time and hassle saver. You want to use a herbicide that is labeled for hack and squirt applications and/or cut stump applications. Many brush control and tough brush herbicides are labeled this way and can be applied using these methods. Herbicides with the active ingredients of triclopyr or glyphosate are the most effective for these methods and readily available for home use. Triclopyr products are usually the most effective on tough brush and woody species. Make sure the species you are targeting is listed on the label and follow the label directions exactly for the methods and concentrations to apply the herbicide correctly.
Oak resprouting from stump after herbicide treatment. Note the deformed leaves on the regrowth showing herbicide damage. Photo Credit: Ian Stone
Cut stump and hack and squirt applications require a bit of a different method of application. Instead of spraying foliage, you apply the herbicide into fresh cuts using a squirt bottle or a paint brush. You should wear proper protective equipment when working with any herbicide and this is also listed in the label. Long sleeves and pants along with chemical resistant gloves and eye protection is usually the minimum recommended. For hack and squirt, make a series of connecting cuts in a ring around the problem stem and squirt the herbicide mixture into the fresh cuts using the squirt bottle. For cut stump treatments cut the stem(s) of the problem tree or shrub off slightly above the ground and apply the mixture using a paint brush or squirt bottle, focusing on the outer portion of the stump right next to the bark. These methods work by introducing the herbicide to the cambium layer, which is the actively growing and live tissue just under the bark in woody plants. By doing this it will travel through the tissue and kill both the roots and stems. It is very important that the cuts are fresh, and the application must be made as soon as possible after the cuts are completed. Once the brush is killed back, you can wait for the stem or stump to rot or remove it once it has completely died. This method is effective at controlling resprouting but is not 100% effective on all applications. If the woody plant in question continues to resprout, you can make fresh cuts and reapply. An advantage of this method is it can be done in winter even when the plant is dormant, as it does not rely on foliage to uptake the herbicide. That means you can use it year-round, and you can take advantage of the cooler winter weather to do this labor-intensive work.
With careful work and proper technique, these methods can be beneficial to control persistent brush problems in the home landscape. When using herbicides it is very important to be aware of off target damage to desirable plants. One of the advantages of hack and squirt and cut stump applications is that they are very targeted and minimize issues with off target damage and drift. Care should be taken not to get the herbicide mixture on the stems of desirable shrubs and trees, and they can penetrate the bark and do damage, especially on thin barked species. If you have questions about how to properly use a herbicide or reading the label contact your local extension office.
by Daniel J. Leonard | Nov 13, 2024
One of my favorite landscape plants is blooming right now in Panhandle landscapes – ‘Soft Caress’ Mahonia. ‘Soft Caress’ was first introduced into the commercial nursery trade in 2006 and included in the Southern Living Plant Collection, but didn’t achieve garden fame until 2013 when it won first place in the Royal Horticultural Society’s (RHS) prestigious Chelsea Flower Show. I first planted a group of ‘Soft Caress’ about ten years ago and as those plants have matured, so too has my appreciation for them. The following are a couple of my favorite outstanding aspects of these small shrubs.
Fall Flowers. Other than camellias, there isn’t a lot else in Panhandle landscapes blooming from mid-November to January and ‘Soft Caress’ Mahonia helps fill that flower void. Brilliant yellow flower spikes rise above the deep-green fernlike foliage and very welcome in this otherwise drab and dreary gardening season.
‘Soft Caress’ Mahonia’s winter flowers are excellent pollinator attractors. Photo courtesy Daniel Leonard.
Quick growing but small statured. If you’ve gardened very long, you’ll know this is a tough ask! Plants that reach mature size relatively rapidly but also don’t get very big are a rare breed. ‘Soft Caress’ Mahonia grows quickly but also maxes out in size rather quickly – mine are very easily maintained at 3-4’ in height with a single annual trim.
~10-year old ‘Soft Caress’ Mahonia Shrub. Photo courtesy Daniel Leonard.
Extremely tough and adaptable. My Mahonia plants have persisted through drought, hurricanes, floods, and freezes and have never looked better. These little plants are simply tough. They’ve had no disease issues and no pest problems (except for a little deer browsing one year, but that appears to be an isolated incident). While they prefer shade, they can also handle several hours of morning sun without incident.
‘Soft Caress’ Mahonia is a standout plant that fills a mostly flowerless period in landscapes, fills its designated landscape spot quickly but won’t outgrow it, and is truly tough. Add a couple to your landscape this winter!
by Sheila Dunning | Nov 6, 2024
Red Maple structure IFAS Photo: Hassing, G.
Though the calendar says November, the weather in Northwest Florida is still producing summer or at least spring-like temperatures. The nice days are wonderful opportunities to accomplish many of those outside landscape chores. But, it is also a good time to start planning for next month’s colder temperatures. Since we don’t experience frozen soil, winter is the best time to transplant hardy trees and shrubs. Deciduous trees establish root systems more quickly while dormant; versus installing them in the spring with all their tender new leaves.
Remove an inch or more for extremely rootbound trees.
Here are a few suggestions for tasks that can be performed this month:
- Plant shade trees, fruit trees, and evergreen shrubs.
- Do major re-shaping of shade trees, if needed, during the winter dormancy.
- Check houseplants for insect pests such as scale, mealy bugs, fungus gnats, whitefly and spider mites.
- Continue to mulch leaves from the lawn. Shred excess leaves and add to planting beds or compost pile.
- Replenish finished compost and mulch in planting beds, preferably before the first freeze.
- Switch sprinkler systems to ‘Manual’ mode for the balance of winter.
- Water thoroughly before a hard freeze to reduce plants’ chances of damage.
- Water lawn and all other plants once every three weeks or so, if supplemental rainfall is less than one inch in a three week period.
- Fertilize pansies and other winter annuals as needed.
- Build protective coverings or moving devices for tender plants before the freeze warming.
- Be sure to clean, sharpen and repair all your garden and lawn tools. Now is also the best time to clean and have your power mower, edger and trimmer serviced.
- Be sure the mower blade is sharpened and balanced as well.
- Provide food and water to the area’s wintering birds.
Mowing a lawn. Photo Credit: University of Florida/IFAS
by Julie McConnell | Oct 31, 2024
A recent visit to the Dothan Area Botanical Garden (DABG) reminded me that although many of our summer flowers are winding down, we have a great garden show coming this winter when the southern classic camellias start to show their stuff. DABG has a large collection of camellias that will start blooming in the coming months. Here is a little background on the two most common types of camellias grown in our area.
Camellia japonica
Also known as Japanese Camellia, C. japonica thrive in partial sun to full shade. Direct morning sun with some shelter from the sun in the hottest part of the day is a good compromise. Too much shade can reduce flowering, so aim for at least partial sun.
Most Japanese Camellias bloom from January to March, but some may start earlier in the season. Flower shapes include single, semi-double, anemone, peony, and formal double. Flower colors are white, pink, red, and sometimes a combination of multiple colors! Camellia japonica mature at 10-15’ tall and wide but may get as big as 25 feet. This makes them ideal to create privacy in the garden or have the lower limbs trimmed into a tree-form.
Camellia sasanqua
Sasanqua camellias also prefer part sun but can also thrive in full sun once established. Leaves and flowers are typically smaller than C. japonica which is an easy way to differentiate. Although most have upright habits and can grow 10-15’ tall as well, there are a few cultivars such as ‘Shishi Gashira’, ‘Bonanza’, and ‘Mine-no-yuki’ that have more horizontal branching making them good options for foundation plantings. Sasanqua camellia are usually in full bloom in the fall, but may bloom as late as January. Flower shapes are similar to C. japonicas, but many varieties have more open flowers with exposed stamens that are beneficial to pollinators.
by Lauren Goldsby | Oct 17, 2024
Orange chrysanthemum flowers in bloom. Photo credit: Lauren Goldsby
It feels like everywhere you turn, chrysanthemums are the star of the show right now. These hardy blooms offer a bounty of fall color to your front porch and seasonal decorations, making them a go-to favorite for sprucing up your space.
We typically see mums offered at garden centers and supermarkets this time of year, with their fall hues of yellow, burgundy, orange, and purple. But here’s the secret: as a perennial plant, mums can do so much more than just serve as a short-lived decoration. With the right care, they can become a permanent part of your landscape, blooming year after year and keeping that fall feeling alive long after the season ends.
To enjoy your mums for more than a few weeks follow these tips!
It’s ok to be picky
When shopping, look for mums with buds that have just started to open and show a hint of color. This ensures you’re choosing the color you want while also increasing the time you can enjoy the flowers at home.
Flowers just starting to open on a chrysanthemum. Photo credit: Lauren Goldsby
Water wisely
While temperatures are cooling down, don’t let that fool you into thinking your mums don’t need regular watering. The middle of the day can still bring heat and producing flowers is energy intensive for the plant. Be sure to check the top inch of soil regularly. If it feels dry, it’s time to water! Mums in full sun may require daily watering but try to avoid getting water on the leaves—this helps prevent pathogens from spreading.
Make room for more bloom
Once flowers have bloomed and begin to fade, it’s important to remove them—this is called deadheading. By trimming away the spent blooms, you’re helping the plant conserve energy and encouraging more new buds to grow. Plus, it keeps the plant looking neat and tidy!
Don’t toss them
When it’s time to make space for poinsettias, simply move your mums to a sunny spot in the yard. Mums can be kept in their containers or planted in the ground. If you’re planting them in the ground and have sandy soil, amend with compost. In late spring, when flowering has ended, prune off the top 2 inches of growth. You can propagate mums by taking vegetative cuttings or dividing the plants.
If you love the look of mums, check out these other plants in the Asteraceae family, many of which are native to Florida. https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/asters/
by Mark Tancig | Oct 4, 2024
One of the best parts about working at the Extension Office is all we learn from the questions we field from curious citizens. I recently had a question about ozone sensitivity in a plant and if that meant it shouldn’t be planted near a street. A little research had me learning all about this interesting topic and finding out that there are even ozone gardens being planted to monitor for air quality.
First of all, ozone (O3), also known as trioxygen, is the name we give when three oxygen molecules form a bond. It is present in low concentrations throughout the atmosphere and is important in absorbing ultraviolet (UV) radiation from the sun. This upper “ozone layer” is what we were concerned about when we noticed a hole forming in it, and regulations were put in place to minimize products that damaged this protective layer. However, ozone can also be formed lower in the atmosphere (called the troposphere) near the surface, where air pollutants, such as those related to the burning of fossil fuels and associated with smog, are produced. In this case, the ozone is considered a pollutant because it can cause health issues for animals, including humans, and can also affect plants.
Good ozone is way above our heads while the bad ozone is near the surface. Credit: National Center for Atmospheric Research.
When toxins in the environment harm plants, we call them phytotoxic. In the case of ozone, it can be phytotoxic at certain levels, and researchers are finding that certain plants seem to be more sensitive to ozone than others. The ozone damages plants by entering through the stoma, very small holes on the bottom of the leaves that the plant uses to pull in carbon dioxide and let out oxygen. Once inside the plant, ozone begins to alter normal cellular function, via oxidation, and causes visible symptoms, especially with the more sensitive plant species.
Symptoms of ozone phytotoxicity on tuliptree (Liriodendron tulipifera). Credit: USDA Forest Service – Region 8 – Southern , USDA Forest Service, Bugwood.org
These particularly sensitive species can be used as biological indicators because they show symptoms that can be easily recognized as ozone injury. Several National Parks and other public gardens have even begun installing ozone gardens, planted with these biological indicator species, to assess the air quality of the area.
Are you interested in knowing the plants that are sensitive to ozone? Here’s a list of species, selected from a National Park Service publication (Ozone Sensitive Plant Species on National Park Service Lands), that grow in the north Florida area:
- Trumpet creeper (Campsis radicans)
- Eastern Redbud (Cercis canadensis)
- Flowering dogwood (Cornus florida)
- Tuliptree (Liriodendron tulipifera)
- American sycamore (Platanus occidentalis)
- Black cherry (Prunus serotina)
- Winged sumac (Rhus copallinum)
- Cutleaf coneflower (Rudbeckia laciniata)
To answer the question that started this path down the ozone rabbit hole, the tree would likely be okay to plant near a road. The tree was not on the research-backed list and the ozone levels in our area generally low. Ozone levels in our part of the state average about 55-60 ppb (parts per billion), compared to the standard of 70 ppb, last set by the US Environmental Protection Agency (EPA) in 2008. Planting the tree may even be a fun, and useful, experiment to keep an eye on local air quality.
Ozone levels, as measured and reported by the Florida Department of Environmental Protection. Source: FDEP.
If you’re interested in more information on the impacts of ozone on plants, the National Center for Atmospheric Research has a great website, including a map of ozone gardens across the country. For more information on ozone levels across the country or in the state of Florida, the US EPA and the Florida Department of Environmental Protection (FDEP) have websites containing useful charts and maps. The good news is that surface ozone levels are generally on the decline thanks to regulations put in place to protect people and the environment. Of course, if you have any plant related questions, please contact your local extension office – we need article ideas!
