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The last several weeks have brought consistently cool weather to the Panhandle, with a few downright cold nights dipping well below freezing. Though winter isn’t officially here, that won’t happen until December 21st, grass mowing season is definitely over and, if you’re like me and didn’t cover your raised bed garden on those nippy nights, vegetable growing has also slowed significantly. So, what are us horticulturally minded folks with cold-weather cabin fever to do? It’s time to take advantage of sweat-free temperatures, break out the shovels and pruners, and get to work in the landscape!
Master Gardeners demonstrate correct tree planting techniques.
The months of December through February are ideal times for planting new trees and shrubs. The reasons for this are simple. Days are short, rain tends to be plentiful, temperatures are cool, and plants are mostly dormant. While newly installed plants need water to become established regardless of when they are planted, demand for supplemental irrigation is significantly less in winter (one of our rainiest seasons) and the chances of a new planting dying from thirst is slim relative to warmer months. Also, planting in winter gives trees and shrubs several months of above ground dormancy to focus their resources below ground, recover from the shock of transitioning from a nursery container into your native soil, and produce valuable roots that will help it get through its first summer. Think about it. Would it be easier for you to start and finish a major outdoor project in July with one bottle of water to drink or in December with an ice chest full? Plants prefer the same!
Not only is winter perfect for planting, tis the season for pruning many species too, deciduous trees (those that lose their leaves in the fall) in particular! The first reason to prune these species in the winter is to give the plants several months to begin healing before growth resumes in spring and insect and disease pressure ramps up again. Many serious pests and diseases of trees are most active during warm, wet weather and all of them have easier access to attack trees through open wounds. Prune in winter to help avoid unwanted pest and disease infestations. Also, dormancy has conveniently knocked the leaves off deciduous species’ branches, allowing us a clear view of the tree’s crown and giving us the ability to make clear, clean, strategic pruning cuts. Proper pruning can help maintain a strong central leader that produces a stately, straight tree and remove dead and diseased branches that could cause problems in the future.
While planting in the winter is always ideal and we just outlined several reasons pruning now can be good, not all plants should be pruned when dormant. For instance, old-fashioned hydrangeas and azaleas that produce blooms from the previous season’s growth. Pruning these in the winter removes all the flower buds that would have bloomed the next summer and what’s the point of an azalea or hydrangea that doesn’t bloom? Also, many small trees and shrubs, like Crape Myrtle and Vitex, may never need pruning if you site them where they will have room to mature without encroaching on other plants or structures.
If you have any questions about planting trees and shrubs, what, when, and how to prune, or any other horticultural topic, please contact your local UF/IFAS Extension Office! Enjoy the weather and happy gardening!
With hurricane season upon us, evidence of preparation is all around us. Tree trimmers, contracted by the local electrical utility companies, have been removing trees, branches and other vegetation that is “too close” to power lines. Many homeowners are concerned over the practice.
In order to prevent power outages, the federally approved Vegetation Management Reliability Standard, FAC-033-2, requires utilities to manage vegetation growth along the path of power lines to prevent contact. A minimum clearance of fourteen (14) feet between trees and transmission lines in the right-of-way must be maintained at all times in order to achieve service reliability and public safety.
By Florida Statute 163, an electric utility is granted easement or right-of-way on private property in order to build and maintain electric power lines. Vegetation maintenance allows for the mowing of vegetation within the right-of-way, removal of trees or brush within the right-of-way and selective removal of tree branches that extend within the right-of-way by the electric utility personnel, licensed contractors or International Society of Arboriculture (ISA) Certified Arborists. The choice of how to trim trees and manage vegetation growth near a power line (e.g. pruning, herbicides, or tree removal) is primarily made by the electric utility, subject to state and local requirements and laws, applicable safety codes, and any limitations or obligations specified in right-of-way agreements. An individual may contact the utility company to obtain a copy of the right-of-way agreement for their property.
Over-pruned trees along power line
Sometimes, it appears to some that excessive vegetation has been removed. But, remember the utility companies are required to maintain the appropriate clearance “at all times.” For example, in the summer, power lines sag as they expand from rising air temperatures and heavy use. Also, wind and future growth must be taken into account when determining where to prune. Electric utilities usually prune or remove vegetation to a distance greater than the minimum clearances to account for all these factors. However, in many instances, removal of the tree would be more aesthetically pleasing and could avoid leaving a hazardous tree in the landscape. But, that is not part of their contract. That decision must be made by the property owner.
Tree trimming around power lines may seem like a local issue, but vegetation growth also affects interstate transmission lines. The U.S. Department of Energy estimates that electric utility service interruptions cost businesses and communities tens of billions of dollars annually. Tree contact with transmission lines was the leading cause of the August 2003 blackout that affected 50 million people in the Northeastern United States and Canada. In fact, that particular blackout prompted Congress to pass the Energy Policy Act of 2005, which lead the Federal Energy Regulatory Commission (FERC) to establish the Vegetation Management Reliability Standard.
Should we have a storm that impacts Northwest Florida, remember that the clearing of trees and branches provides faster access for first responders, line repair crews, and other emergency service personnel. So, as you watch the preparation work being done, think about where you will be planting a tree so that it can reach full maturity without threatening power lines, therefore, not requiring “ugly pruning!”
Spacing between trees and power lines
The urban forest is much different from a natural forest. Trees often develop a form that is more susceptible to breakage when grown in developed commercial and residential environments. As a result, trees need preventive pruning to develop strong structure. Research and observation show that well pruned trees can create a more wind resistant urban forest.
Pruning to create stronger tree structure is an ongoing process. To minimize the likelihood of tree damage it is necessary to reduce the length of limbs with a weak attachment to the trunk and to balance the canopy by reducing the length of limbs on the side where weight is concentrated. Do not remove interior branches, as this concentrates foliage at the tips of branches and causes them to break in strong winds.
Limbs that are more than ½ the diameter of the trunk and multiple trunks of similar size must be reduced in order to form strong branch unions and eliminate co-dominant leaders. A reduction cut is pruned back to a smaller lateral branch. Good pruning cuts avoid cutting into the collar. The collar is the swollen area at the base of the branch where it joins the trunk. The tissue is rich in energy reserves and chemicals that hinder the spread of decay.
Preventative pruning only applies to woody tree species. Palms need fronds to protect the bud and provide nutrients for growth. Arborists report that results from previous storms revealed that palms that had been “hurricane pruned” suffered more damage than those that were not pruned. Do not wait until the last minute to prepare your trees for hurricane season. Take action now. For more information on pruning visit: http://hort.ifas.ufl.edu/woody/pruning.shtml.
I live in the woods, so I mainly have a “natural” landscape. I remove trees, shrubs, and weeds as I see fit, but for the most part things just grow wild. However, there are a few spots in the yard where the previous owners did a little landscaping. Unfortunately, these spots have become a bit overgrown. One spot in particular features some gardenia plants around the HVAC units. At first, I was a little hesitant to prune these shrubs because they provide some shade to the units. However, they have become overgrown and I know they will grow back. I was patient to wait for them to finish flowering.
A gardenia shrub that has become a bit overgrown. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
As you can see in the photo above, this gardenia has become a bit leggy. It is important to also note the good amount of branching and new growth at the base of the plant. There are a few pruning options available for shaping shrubs such as hedging/terminal pruning, selective pruning, and renewal pruning. While a tree form gardenia can be attractive, it wasn’t desired in this situation. This particular case called for renewal pruning to improve the form of the plant. Renewal pruning is probably the easiest type of pruning, because it requires the least amount of thinking. It basically involves removing the majority of old growth.
A gardenia shrub that has been renewal pruned. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
The picture above is of the same shrub that has been pruned heavily. Not only have the older, leggy branches been removed, but some of the newer growth has been removed to allow for better air circulation within the shrub. This will help reduce the incidence of disease.
A gardenia shrub six weeks after renewal pruning. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Six weeks after being pruned, this shrub is flowering for a second time. In a matter of short time it will be providing much needed shade for the HVAC units again. (That is..if I remember to selectively prune throughout the year.) For more information on how to prune and what to prune, please visit the UF/IFAS Gardening Solutions page on pruning.
Loquat trees provide nice fall color with creamy yellow buds and white flowers on their long terminal panicles. These small (20 to 35 ft. tall) evergreen trees are native to China and first appeared in Southern landscapes in the late 19th Century. They are grown commercially in subtropical and Mediterranean areas of the world and small production acreage can be found in California. They are cold tolerant down to temperatures of 8 degrees Fahrenheit, but they will drop their flowers or fruit if temperatures dip below 27 degrees Fahrenheit.
A beautiful loquat specimen at the UF/IFAS Extension at Santa Rosa County. Photo Credit: Matt Lollar, University of Florida/IFAS – Santa Rosa County
Leaves – The leaf configuration on loquat trees is classified as whorled. The leaf shape is lanceolate and the color is dark green with a nice soft brown surface underneath. These features help give the trees their tropical appearance.
Flowers – 30 to 100 flowers can be present on each terminal panicle. Individual flowers are roughly half an inch in diameter and have white petals.
Fruit – What surprises most people is that loquats are more closely related to apples and peaches than any tropical fruit. Fruit are classified as pomes and appear in clusters ranging from 4 to 30 depending on variety and fruit size. They are rounded to ovate in shape and are usually between 1.5 and 3 inches in length. Fruit are light yellow to orange in color and contain one to many seeds.
A cluster of loquat flowers/buds being pollinated by a honey bee. Photo Credit: Matt Lollar, University of Florida/IFAS – Santa Rosa County
Propagation – Loquat trees are easily propagated by seed, as you will notice as soon as your tree first bears fruit. Seedlings pop up throughout yards containing even just one loquat tree. It is important to note that the trees do not come true from seed and they go through a 6- to 8-year juvenile period before flowering and fruiting. Propagation by cuttings or air layering is more difficult but rewarding, because vegitatively-propagated trees bear fruit within two years of planting. Sometimes mature trees are top-worked (grafted at the terminal ends of branches) to produce a more desirable fruit cultivar.
Loquat trees are hardy, provide an aesthetic focal point to the landscape, and produce a tasty fruit. For more information on growing loquats and a comprehensive list of cultivars, please visit the UF EDIS Publication:Loquat Growing in the Florida Home Landscape.
A couple weeks ago, I was on a site visit to check out some issues on Canary Island Date Palms. The account manager on the property requested a site visit because he thought the palms were infested with scale insects. He noticed the issue on a number of the properties he manages and he was concerned it was an epidemic. From a distance, lower fronds were yellowing from the outside in and the tips were necrotic. These are signs of potassium deficiency with possible magnesium deficiency mixed in.
Transitional leaf showing potassium deficiency (tip) and magnesium deficiency (base) symptoms. Photo Credit: T.K. Broschat, University of Florida/IFAS Extension
Nutrient deficiencies are slow to correct in palm trees. It’s much easier to prevent deficiencies from occurring by using a palm fertilizer that has the analysis 8N-2P2O5-12K2O+4Mg with micronutrients. Even if the palms are part of a landscape which includes turf and other plants that require additional nitrogen, it is best to use a palm fertilizer with the analysis previously listed over a radius at least 25 feet out from the palms. However, poor nutrition wasn’t the only problem with these palms.
Upon closer look, the leaflets were speckled with little bumps. Each bump had a little white tail. These are the fruiting structures of graphiola leaf spot also known as false smut.
Graphiola leaf spot (false smut) on a Canary Island Date Palm. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Graphiola leaf spot is a fungal leaf disease caused by Graphiola phoenicis. Canary Island Date Palms are especially susceptible to this disease. Graphiola leaf spot is primarily an aesthetic issue and doesn’t cause much harm to the palms infected. In fact, the nutrient deficiencies observed in these palms are much more detrimental to their health.
Graphiola leaf spot affects the lower fronds first. If the diseased, lower fronds are not showing signs of nutrient deficiencies then they can be pruned off and removed from the site. All naturally fallen fronds should be removed from the site to reduce the likelihood of fungal spores being splashed onto the healthy, living fronds. A fungicide containing copper can be applied to help prevent the spread of the disease, but it will not cure the infected fronds. Palms can be a beautiful addition to the landscape and most diseases and abiotic disorders can be managed and prevented with proper pruning, correct fertilizer rates, and precise irrigation.