by Matthew Orwat | Sep 17, 2019
Fall Pruned Azalea. Image Credit Matthew Orwat
Although Northwest Florida is well known for its beautiful Azalea displays every spring, many do not understand that these shows of bloom could be sacrificed completely by pruning at the wrong time.
Pruning Azaleas in the fall will result in a loss of spring bloom the following spring, since flower buds are initialized on previous year’s growth for most azalea cultivars.This means that they flower on growth put on throughout the previous growing season. If a gardener removes the previous season’s new growth, they are removing the blooms as well.
So, when is the proper time to prune Azaleas? The ideal time to prune is directly after the spring bloom. This will give the plant enough time to generate abundant new growth, thus maximizing bloom next spring. One might think that when growing the repeat blooming Encore azaleas, pruning time doesn’t matter. Should the need arise to prune these compact, repeat blooming shrubs the optimal time is directly after spring bloom and not after the final fall bloom cycle.
For more information on pruning Azaleas or on general Azalea culture, please read the UF / IFAS publication Azaleas at a Glance or check out the Pruning Azalea page on Gardening Solutions.
by Mark Tancig | Mar 6, 2019
Azaleas are a beautiful shrub for the north Florida landscape, especially if pruned properly. Source: Larry Williams, UF/IFAS
The sight of azaleas in the north Florida spring just makes you feel good. They are so vibrant, and with such variation, that you can’t take your eyes off them. As an appreciator of these beautiful displays of color, nothing pains me more than to see an improperly pruned azalea during this time. If you must prune your azaleas, please, please only prune them once a year and only soon after flowering has ended! This public service announcement will hopefully ensure we all get to see the full azalea show. Otherwise, we’ll be left with mostly green hedges, some flowers uncomfortably tucked in the interior of the plants, or flowers poking out the sides like a middle-aged man’s balding head.
If pruned properly and at the right time, this azalea shrub would be a mass of flowers. Source: Mark Tancig, UF/IFAS.
The common flowering azaleas in landscaped settings are native to Japan and a relative of blueberries. They comprise many different hybrids, cultivars, and varieties of plants in the genus Rhododendron (Greek for rose-tree) and have been cultivated for centuries. Long ago, I’m sure, those who studied plants and tinkered with azaleas realized that their vegetative growth (new leaves and stems) ends soon after flower bud initiation. This means that later prunings, or multiple prunings throughout the year, will be taking off more developing flower buds than new leaf and stem growth.
To prevent depriving us all of less flowers, consider why – or if – they need pruning in the first place. Proper planning and planting can prevent azaleas, which naturally want to be a sprawling shrub, from growing into the sidewalk or driveway. If you’ve inherited azaleas that may be the right plant, but slightly in the wrong place, they can be heavily pruned every couple of years to keep them in check, and can even be transplanted. Azaleas are not a good choice for formal hedges. If given the right place and enough space, the only required pruning would be dead, diseased, or crossing branches.
If you decide you need to prune – whether to knock back for space or for general shape – only bust out the loppers once the flowers have withered on the ground… and then lock those loppers away so that you won’t be tempted. If you have landscapers working for you, remind them to keep the hedge trimmers away from the azaleas.
Azaleas are vibrant, even in black and white! Source: Florida State Archives, Florida Memory Project.
For the love of flowers, please prune azaleas thoughtfully, and share this information with others
P.S. We also have several species of native azaleas (including Rhododendron austrinum and Rhododendron canescens) that can be a beautiful addition to the landscape.
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 Sheila Dunning | Mar 20, 2017
Now is the time to prevent your azaleas from being attacked by lace bugs. The azalea lace bug, Stephanitis pyrioides, overwinters as eggs on the underside of infested leaves. Eggs hatch in late March and early April. The insect then passes through five nymphal instars before becoming an adult. It takes approximately one month for the insect to complete development from egg to adult and there are at least four generations per year. Valuable plants that are susceptible to lace bug damage should be inspected in the early spring for the presence of overwintering lace bug adults, eggs and newly hatched nymphs. Inspect these plants every two weeks during the growing season for developing lace bug infestations.
Both adults and nymphs have piercing-sucking mouthparts and remove sap as they feed from the underside of the leaf. Lace bug damage to the foliage detracts greatly from the plants’ beauty, reduces the plants’ ability to produce food, decreases plant vigor and causes the plant to be more susceptible to damage by other insects, diseases or unfavorable weather conditions. The azalea can become almost silver or bleached in appearance from the feeding lace bug damage.
However, lace bugs often go undetected until the infested plants show severe damage sometime into the summer. By then several generations of lace bugs have been weakening the plant. Inspecting early in the spring and simply washing them off the underside of the leaves can help to avoid damage later and the need for pesticides.
Adult lace bugs are flattened and rectangular in shape measuring 1/8 to 1/4 inch long. The area behind the head and the wing covers form a broadened, lace-like body covering. The wings are light amber to transparent in color. Lace bugs leave behind spiny black spots of frass (excrement).
Lace bug nymphs are flat and oval in shape with spines projecting from their bodies in all directions. A lace bug nymph goes through five growth stages (instars) before becoming an adult. At each stage the nymph sheds its skin (molts) and these old skins often remain attached to the lower surface of infested leaves.
Azalea lace bug eggs are football-shaped and are transparent to cream-colored. Lace bug eggs are found on the lower leaf surface, usually alongside or inserted into a leaf vein. Adult females secrete a varnish-like substance over the eggs that hardens into a scab-like protective covering.
For more information go to: http://entomology.ifas.ufl.edu/creatures/orn/shrubs/azalea_lace_bug.htm
by Les Harrison | Feb 3, 2017
Photo caption: Local azaleas were prematurely blooming
This winter’s exceptional weather has deceived some popular springtime ornamental shrubs and fruit trees into flowering prematurely. Azaleas, for example, began blooming because of winter temperatures mush warmer than average.
There are number of variables which determine when a plant will bloom each year, including the sun, water, and air temperature. To understand why the plants bloom, there should be an understanding of “photoperiodism”, meaning the effects of light and darkness on some plant species.
Certain plants respond to the day length. Some are long day plants which flower in spring and summer, and some are short day plants flowering in fall and winter. Then there are plants which will bloom in any season, identified as day neutral plants.
Long and short day plants will not be directly affected by prevailing weather conditions. For example chrysanthemums, which are short day plant naturally bloom in winter.
These plants can be forced to bloom in summer by keeping them in a dark room for 12 hours a day for several weeks. Many nurseries supplying florist uses this technique and utilize greenhouses with blackout systems. They also use grow lights to produce early season blooms on spring/summer flowers sold for Valentine Day.
For those neutral day plants there is “vernalization”. These plants must be exposed to cold weather to some greater or lesser amount.
Most temperate fruit trees need exposure to cold temperatures. When winters are too mild or contain intermittent warmer periods, dormancy is prematurely terminated and bud break starts.
Most of the exposed buds of these fruit trees can survive freezing temperatures, but many of their flowers will be killed if exposed to a late arriving hard freeze or frost.
After the freeze most of the flowers may appear normal, but the center part of the flower where the reproductive organs reside are killed and result in no fruit formation. Covering plants in-bloom provides some freeze protection.
With a warm early winter, like December 2016, there has been irregular and premature flowering.
Another consideration is fruit trees or shrubs pruned too early winter. Warm weather combined with the pruning stimulates the growth of new shoots.
There is a hormone produced in lateral or terminal shoot buds which travels down the shoots inhibiting their growth. When the terminal shoots are pruned too early the growth inhibiting hormone is removed.
The warm days during winter may cause these newly pruned plants to form new shoots. The new growth is tender and very susceptible to freeze injuries. Pruning in late January or February will likely deliver the best results.
For shrubs like azaleas and gardenias, flower buds are set in summer, long before they can be identified by most people. Losing the buds, no matter the cause, after midsummer drastically decreases the number of flowers the following spring.
To learn more about the spring bloom for 2017, visit the UF/IFAS County Extension website
By: Gohar Umar, FAMU Extension Horticulture Specialist, and Les Harrison, Wakulla County Extension Director
Photo caption: Local azaleas were prematurely blooming
