by Larry Williams | Aug 20, 2018
Hydrangea leaf spot disease
Photo credit: Larry Williams
It is not uncommon to see leaf spots on your hydrangeas during late summer and fall.
These spots are caused by a number of fungal diseases. Plant fungi and wet weather go hand-in-hand. Florida’s high humidity, heavy dews and frequent rains during spring and summer provide perfect conditions to allow fungal diseases to flourish. Bacterial leaf spots can be part of this foliage disease mix, too.
Common foliage diseases seen on hydrangeas this time of year include Phyllosticta leaf spot, Target leaf spot, Bacterial leaf spot, Botrytis and Cercospora leaf spot.
These foliage diseases are the norm rather than the exception as we move into the wet summer months and on into fall. As a matter of fact, you would be hard-pressed to find any hydrangea in our area without some evidence of infection now.
This late in the year it is more of a “grin and bear it” problem. In other words, it’s too late to do much about the fact that your hydrangea plant has leaves covered in ugly spots. By now many of the infected leaves are turning brown, withering and dropping prematurely from the plant.
Cercospora leaf spot is one of the most common foliage diseases of hydrangeas. Along with most of the leaf spot diseases, it begins as small dark-colored specks on the leaves. The small specks generally go unnoticed. But as the spots continue to slowly enlarge, mostly maintaining a circular shape, they become more obvious. With heavy infection, individual spots can coalesce forming larger irregular shaped brown areas on individual leaves. The individual spots may have a purplish halo with gray center.
There are some fungicides that can help prevent these leaf spots. But you’d have to begin treatment early in spring before any leaf spots exist and spray the plant every 10 to 14 days during favorable disease development (humid, rainy weather), which is pretty much our spring and summer months. These types of diseases are prevented, not cured. That’s the “grin and bear it” part of waiting until now.
The fungus survives on infected leaves. So, the best thing to do now is to remove and dispose of infected leaves. Also, be careful to not wet the leaves when irrigating the plants during the growing season.
New leaves of spring should be spot/disease free as they emerge. But the cycle of life for these leaf spot diseases will again result in spotted/diseased leaves on your hydrangeas next summer and fall without persistent treatment.
The good news is that these leaf spot diseases normally do not cause permanent/long-term damage for hydrangeas. They just make the plant look ugly.
by Daniel J. Leonard | Jul 3, 2018
Each time I travel to central and south Florida and observe the wonderfully flamboyant tropical flora, I am reminded of the unique and frustrating climatic characteristics of Northwest Florida. Our weather is tropical enough through the summer to sustain virtually everything our friends to the south grow, but winters north of the Big Bend are just cold enough to prevent long-term success with most tropical species. However, the genus that is maybe most synonymous with tropical color, the Hibiscus (it even has its own texting emoji!), contains several species that are hardy through our winters. The best landscape plant of these hardy Hibiscus species is creatively (sarcasm) called Hardy Hibiscus or Giant Rose Mallow (Hibiscus moscheutos) and is an absolute star in the Panhandle, bringing the beauty of the tropics to your yard!
Hibiscus ‘Starry Starry Night’ – Photo courtesy Daniel Leonard
Rose Mallow is a native perennial species that occurs in sunny wetlands across the eastern U.S. This species can grow 7-8’ in height in its natural, unimproved state and possesses the largest flowers of any hardy perennial, some varieties easily eclipse 12” in diameter. Rose Mallows bloom through the heat of our long summers and return reliably each winter unfazed by frost. The flowers also happen to be a favorite of butterflies and hummingbirds and bring beneficial wildlife to the landscape. These characteristics and the trend towards the use of pollinator friendly, low-maintenance native perennials in landscapes quickly made Rose Mallow a jewel for plant breeders and now virtually all major horticultural brands have a line of Hardy Hibiscus available at garden centers, in varying sizes, flower color and leaf color/form. Recent breeding efforts have focused on introducing plants with enormous, richly colored flowers held on compact plants with attractive foliage. The results have yielded two series and three individual cultivars that I consider superior selections and are more than worthy of inclusion in your garden:
- Summerific® Series by Proven Winners. This series is comprised of four robust (up to 5’ in height) cultivars, ‘Cherry Cheesecake’ (bicolor magenta and white flowers), ‘Berry Awesome’ (purplish lavender flowers), ‘Cranberry Crush’ (a red you really have to see to believe), and ‘Perfect Storm’ (notable for its deep purple foliage).
- Luna Series by Monrovia. This series is notable for its ultra-compact (3’ in height or less) size and characteristically large flowers. It is also composed of four cultivars, ‘Luna Red’ (deep red), ‘Luna Blush’ (white, fading to pink near flower margins), ‘Luna Pink Swirl’ (pictured and my favorite, bicolor swirly flowers), and ‘Luna White’ (white with a red center).
Hibiscus ‘Luna Pink Swirl’ – Photo courtesy Daniel Leonard
- ‘Starry Starry Night’ by Walter’s Gardens. (Pictured) This cultivar combines dark purple to black leaves with swirled pale and dark pink flowers. It has performed very well in my landscape and if I could only grow one, this might be it.
- ‘Lord Baltimore.’ The classic, large growing cultivar with bright red flowers that is widely available and easily found. An oldie (introduced in 1955) but a goodie.
- ‘Midnight Marvel’ by Walter’s Gardens. A “hot off the press” new cultivar that is currently difficult to find due to popularity, though some online outlets have them available in small sizes. This one is worth your patience. Sporting deep red blooms on near black foliage, there’s nothing else like it in the landscape.
In addition to being gorgeous plants, Rose Mallows are extremely versatile in the landscape and could not be easier to grow. Because the size varies so greatly (from the diminutive 30” tall ‘Luna’ series to the 8’ tall unimproved species), there really is a place for one in every garden. I like to use the smaller cultivars in large containers to facilitate moving them around where their floral display has the greatest impact or to create a tropical effect where in ground plantings are not an option (pool decks, patios, etc). The larger cultivars make spectacular specimen plantings in perennial and shrub beds and even make a really dense, striking hedge (just know they disappear in the winter). Be sure to give them as much sun as possible, as this will enhance the number of flowers on each plant and darken the foliage on the cultivars with purplish/black leaves. Too little sun will result in fewer flowers and lighter green foliage. As wetland plants, Rose Mallows enjoy regular water, either from rainfall or irrigation; they will let you know when they need it – their large leaves readily wilt under drought stress, somewhat like Hydrangea.
For low-maintenance, native, pollinator friendly, cold-hardy tropical color, you need look no further than Rose Mallow. These perennial shrubs come in all sizes and colors and fit any landscape! Look for the above listed series and cultivars at better garden centers and online retailers and enjoy the oohs and ahhs elicited when people first get a glimpse of Hardy Hibiscus in your landscape! Happy Gardening!
by Molly Jameson | Jun 21, 2018
Mrs. Henry C. Mills in 1966 with her African violets at the North Florida Fair
flower show. Photo by Dan Stainer/State Archives of Florida.
Growing up, as soon as I entered the fair gates, I always headed straight for the rides. If I was lucky, I was able to get an unlimited pass strapped around my wrist and didn’t need to worry about rationing any tickets. Although I usually didn’t remember the names of particular rides – they were clear in my imagination. The spaceship, the circular mini roller coaster, the alien arms… and of course, the Ferris wheel. It wasn’t until I was about a dozen rides in – and starting to feel a little queasy – that the fun houses and win-a-goldfish-by-throwing-a-ring or shoot-a-basketball-for-a-giant-stuffed-tiger games drew my attention. After that, I was ready for funnel cake. Maybe even a corn dog and an assortment of fried cheese, pickles, and the like. Inevitably, I would eat too much and be out of commission for any more rides I was hoping to squeeze in – or squeeze into! This is when I might finally make my rounds through one or two of the giant warehouse-looking buildings that lined the way to the exits, where I knew there was at least a llama or a goat to be fed at the petting zoo.
Instead of simply attending the North Florida Fair this year, submit your garden’s best for competition. Photo by North Florida Fair.
But when I started volunteering at the Leon County Animal Shelter as part of the 4-H Pet Partners at age 12, I was introduced to these buildings in a whole new light. We were assigned the task of creating papier-mâché cats and dogs to display at the fair to help build awareness of pet overpopulation. I remember my dog well – he was beagle-like, with long droopy paper ears and stiff pointy legs that I struggled to keep balanced. The day we went to set up our display, my adrenaline soared, as I knew our creations were to be judged and ribbons to be bestowed. Ever since, I no longer view the fair buildings as a last stop – rather, I relish my stroll through each of them, as they contain so many handmade treasures, many of which are adorned with blue rosettes of triumph.
The tradition of displaying and competing for the best quality handiworks at the fair goes all the way back to the Middle Ages and Renaissance, where merchants sold and traded agricultural goods that had been grown over the summer and freshly harvested in the fall. Naturally, competitions arose during these times, as they strove for the finest products.
Today, fairs reflect the personality of an area, and nearly universally include judges who inspect home grown fruits and vegetables, flowers, preserved foods, and baked goods entered into competition by the community. The North Florida Fair awards about $80,000 in cash prizes to citizens who create and grow various items. Anyone living within the 24 counties that comprise North Florida – from the Suwannee, west to the Alabama line – is eligible to enter as many of the exhibit categories as they would like.
A youth showcasing his prize winning chicken at the North Florida Fair. Photo by Aly Donovan.
The exhibits are arranged into various departments, such as Home Agriculture, Capital City Garden Club Flower Show, Poultry, Baked Goods, and Fine Arts and Crafts. Within each department, there are various classes that are split into certain age divisions (i.e., youth only) or experience levels (i.e., amateur vs. professional). Under the Home Agriculture department there are 42 classes, including 13 classes covering fresh vegetables. The Capital City Garden Club Flower Show department has 13 classes, including annuals, perennials, hanging baskets, fruiting shrubs, trees, and vines, succulents, and much more. If you would like to submit something you’ve grown, now is the time to begin planning, as this year’s fair is set for November 8-18.
All of the details for each department and class can be found on the North Florida Fair website (http://northfloridafair.com/), under the Exhibitors tab. Pay close attention to the application and submittal deadlines for each specific category, as most items are due for judging the week prior to the fair opening.
So, let nostalgia win you over as you prepare your home-grown vegetables and flowers for submittal to the North Florida Fair. You might just earn a blue ribbon to be displayed for all fair attendees to admire, either as they walk off a full stomach in preparation for more rides, on their way to the exits, or just as they get started creating their own fond fair memories.
by Julie McConnell | May 23, 2018
Dr. Steve Johnson, UF/IFAS Associate Professor of Wildlife Ecology will be the featured speaker on June 6th
June 6th is a great day to learn about all types of invasive species that threaten natural areas in Northwest Florida!
The UF/IFAS Extension Bay County office will have multiple educational exhibits with living samples of species of concern from 9 a.m. – 5 p.m. on Wednesday, June 6th. This is a multi-agency effort to inform citizens about the impact of invasive plants and animals and how they can help reduce introduction and spread. For full details see the Bay_Invasive Workshop Flyer
We are pleased to announce our partners Florida Fish and Wildlife Conservation Commission (FWC) and Science and Discovery Center of Northwest Florida will be on hand to share information about caring for exotic pets and current management plans for invasive species such as Lionfish, Aquatic Weeds, and how to surrender an animal on designated Pet Amnesty Days.
At noon there will be a special guest speaker for a bring your own lunch & learn “Exotic Invaders: Reptiles and Amphibians of Concern in NW FL.” Dr. Steven Johnson, UF/IFAS Associate Professor of Wildlife Ecology, will talk about exotic reptiles and amphibians we should be aware of that may occur in our area.
In the morning, we will be focusing on the invasive air potato vine with the distribution of air potato leaf beetles for biological control. Need air potato leaf beetles to manage the air potato vine on your property? Please register here http://bit.ly/bayairpotato to receive beetles – they will be distributed from 9 a.m. – noon on June 6th.
Learn more about the success of the Air Potato Biological Control program at http://bcrcl.ifas.ufl.edu/airpotatobiologicalcontrol.shtml
#invasivespecies
by Les Harrison | May 23, 2018
There is something to be said for being a longtime resident. While it does limit ones outlook from a global perspective, it promotes focus on perfecting applicable traits which are close to home.
Azalea and bug: Wild Piedmont Azaleas (Rhododendron canescens) and a bumble bee.
The unique, and very pleasant, environment of north Florida is an excellent example of near perfection on a localized basis. The weather (within reason), the fauna and the flora are tailored to a superior quality of life, especially the spring blooming native plants.
The human residents of the panhandle can easily see this in a native plant which blooms in the spring. Wild azaleas make random appearances, but their cultivated cousins from Asia are now the province of retail establishments.
Azaleas are member of the Rhododendron genus which includes flowering shrubs of the same name which grow in more northern latitudes. Their popularity as flowering perennials has led to the development of more than 10,000 cultivars worldwide which please almost every taste for a profuse and showy burst of color.
These plants have species native to southwest Europe, Asia, and North America. They are believed to date back 70 million years and have an ancestor in common with blueberries and pieris.
Many of the azaleas which grace the yards and gardens in the southeast are traced back to east Asian stock. These cultivars had been grown for millennia, but reached Europe in the early 17th Century when wealthy estate owners were seeking a new and unique look to their landscapes.
When azaleas arrived in America there were 26 different native azaleas already growing here. At least four of these grow naturally in Florida and can be presently seen in natural settings, as well as, managed landscapes.
Like the long cultivated Asian varieties, the azaleas native to Florida prefer acidic soils and filtered light. The can be found in forested areas and near streams or rivers.
The native azaleas are rather scraggly and upright when very young, but will spread out and fill in as they mature. The large, dark green leaves bend the branches gently to form a cascading appearance down to the ground.
A single specimen in a formal landscape should be allowed at least four to five feet of spread to develop into its natural form. These plants are very sensitive to dry soil, but the soil should drain freely of excessive moisture.
A thick mulch of three inches deep is recommended to help ensure adequate root growth when cultivated out of their natural environment. Roots are located in the top several inches, even in well-drained sandy soils, so adequate mulching is critical to success.
Pruning of these natives is seldom necessary except to control shoots extending above the normally mounded shape. Azaleas bloom on the previous year’s growth so any pruning should be done after flowering, but before July.
Mass azalea plantings add a stark color contrast to any landscape. The green background of March and April with clusters of boldly bright blossoms is a striking sight.
The wild azaleas add an enduring continuity to the ever-changing landscape in contemporary life. Some things should never change, especially in comfortable north Florida.
by Daniel J. Leonard | May 4, 2018
H. macrophylla ‘Bloomstruck’
Photo courtesy of Andrea Schnapp
Generally, when folks find out what I do for a living, among the first questions asked is “What is your favorite plant?” Being somewhat of a plant nerd, that can be a tough question to answer! However, I usually circle back to the same answer, “Hydrangea”. There are many reasons my fellow gardeners and I love hydrangeas. It’s undeniable that few plants conjure more fond memories of summers gone by or cause more impulse purchasing at nurseries than a hydrangea in full, billowy bloom. Additionally, few specimen shrubs give more floral firepower and ask so little of the gardener in return. My own love affair with hydrangea stems from my first propagation experience, a softwood cutting of Hydrangea macrophylla ‘Nikko Blue’ (taken with the help of someone who knew a lot more about what they were doing than I did) that, seemingly magically, sprouted roots in a makeshift greenhouse, a cypress box with an old, crusty, sliding glass door. Hydrangeas hooked me. However, even with all of those attributes to its name, Hydrangea, as a genus, remains underappreciated and underutilized in modern landscapes. Let’s shed some light on the two primary reasons for gardeners’ failure and frustration with hydrangeas in the landscape and highlight some of the best Hydrangea species and cultivars to look for at the nursery!
First, hydrangea has a reputation as being a high water user. As the name (hydrangea comes from “hydor”, which is Greek for water) might suggest, hydrangeas are indeed water sensitive. However, this does not necessarily mean they require more or less water than other plants, rather they simply betray drought quicker than most other plants. This feature makes hydrangea particularly useful in the landscape as an indicator plant. As a general rule, hydrangeas (particularly those planted in too much sun) wilt in the afternoon heat; this is totally normal. However, if the plants remain wilted the next morning, it is an indicator to the gardener that irrigation is required! If they don’t get irrigation soon after telling you they need it, the plants may begin to decline. Rather than being viewed as a drawback, think of this feature as an early warning system. Name another plant that looks out for us gardeners like that!
The second primary reason people fail with hydrandea is improper site selection. Attempting to grow hydrangea in full sun in Florida leads to less than spectacular results. All species of hydrangeas are most happy when sited to receive at least some afternoon shade, if not filtered shade throughout the entire day. Exposure to blistering afternoon sun is problematic and results in increased wilting from heat stress, increased irrigation requirements and “bleached” flower coloration. Remember, there are fewer frustrating things than growing the right plant in the wrong place!
Now that you know how not to fail with hydrangeas, it’s time to select the proper plant for your property! Three primary species perform noticeably better here than the rest of their kin and deserve the gardener’s consideration in Northwest Florida: H. macrophylla (Bigleaf Hydrangea), H. quercifolia (Oakleaf Hydrangea), and H. paniculata (Panicle Hydrangea).
H. macrophylla
H. macrophylla, the old-fashioned hydrangea everyone’s grandmother grew, is truly one of the standouts in the shady, Southern landscape and commands attention when in flower. Sporting giant “mopheads” of inflorescences in gorgeous hues of blue (or pink, depending on soil pH), H. macrophylla is an extremely low maintenance plant, requiring only periodic irrigation and infrequent fertilizer; H. macrophylla even tolerates salt spray and can be grown on the Gulf Coast! By far, the greatest percentage of questions I receive concerning H. macrophylla involve plants not flowering because of pruning at the wrong time of year. For best flowering results, time pruning of once-blooming traditional cultivars like ‘Nikko Blue’ soon after flowering is finished in late summer. These plants set flower buds on the previous season’s wood; pruning older cultivars in the fall or winter may rejuvenate the plant but will prevent flowering the next year! Fortunately, over the last twenty years, advances in Hydrangea breeding have given gardeners the option of planting remontant cultivars that bloom on current season’s wood. Commonly sold remontant cultivars like ‘Endless Summer’, ‘Penny Mac’, ‘Bloomstruck’, and ‘All Summer Beauty’ have an early summer flower display like the traditional types but then continue to flower periodically throughout the rest of the summer! Even better, they may be pruned at any time without worry of damaging the next season’s flower show!
H. quercifolia (Oakleaf Hydrangea) Photo Courtesty of Andrea Schnapp
Those looking to diversify their hydrangea collection should next look to the native Oakleaf Hydrangea (H. quercifolia). The Oakleaf Hydrangea is a Florida native, growing wild on the steep, shady ravines along the northern end of the Apalachicola River. If the plants never flowered, the Oakleaf would be worth planting; its massive leaves, oak-shaped as the name suggests, can grow up to a foot in length and provide some of the best fall foliage color available to Floridians. However, the real show, as with all hydrangea species, are the flowers. This species flaunts 8”-10” white, panicle shaped flowers that are held elegantly above the coarsely textured foliage. In addition to these features, Oakleaf Hydrangeas couldn’t be easier to grow; obtaining heights up to 10’ and asking very little of the gardener other than adequate irrigation and some shade in the heat of the day! Look for the author’s favorite cultivars: ‘Alice’, ‘Semmes Beauty’, and ‘Snowflake’. Each of these cultivars and selections of the common species H. quercifolia perform very well in Northwest Florida.
H. paniculata ‘Quickfire’
Photo courtesy of Andrea Schnapp.
Finally, the newest hydrangea species introduced to Florida gardens, H. paniculata, has made significant inroads in the landscape industry over the last decade. Primarily grown as the cultivar ‘Limelight’, H. paniculata overcomes some of the weaknesses of the two aforementioned species, namely it tolerates full-sun and persists on much less water, making it a potentially more sustainable plant for many landscapes. This plant, like the remontant H. macrophylla cultivars, blooms on new wood and even seems to enjoy a hard pruning each winter; plants pruned this way seem to be more vigorous the next season and produce larger greenish-white flower panicles than unpruned specimens. Though it is a relative newcomer, H. paniculata, particularly ‘Limelight’, is a worthy addition to any landscape.
As you can see, there is a hydrangea for every yard and no true Southern landscape is complete without a few. When perusing your local garden center this summer, look for the selections and species mentioned above, plant properly, and enjoy the ensuing annual flower show for many years into the future! Who knows, you may be hooked by hydrangeas as I once was!
