by Carrie Stevenson | Mar 26, 2018
Ah, the oft-ignored pine tree. They are so ubiquitous throughout the southeast, that many people consider them undesirable in a landscape. Having grown up near the “Pine Belt” of Mississippi, I figured I knew plenty about them, but this week I learned something new. While on a field tour with local foresters in the business of loblolly and longleaf pine farming, they introduced me to the pine tip moth. These insects can wreak havoc on valuable young pine trees.
Dead branch tip and needle damage caused by pine tip moths. Photo credit: Carrie Stevenson, UF IFAS Extension
Hollow space in pine tree branch created by pine tip moth. Photo credit: Carrie Stevenson, UF IFAS Extension
Female pine tip moths lay eggs on the growing end of a pine branch—particularly young, healthy loblolly and shortleaf (longleaf is rarely affected). When the eggs hatch 5-30 days later, the larvae start feeding. They tunnel into the shoot and bud of the pines, feeding on the tissue and burrowing a hollow cavity for several weeks. The larvae then pupate inside the space until becoming adult moths, exiting from the hole they created. The cycle restarts, with more adult moths, eggs and larvae.
Adult Nantucket pine tip moth Rhyacionia frustrana (Comstock). Photograph by James A. Richmond, USDA Forest Service, www.Forestryimages.org.
Two insect species are most common in our area; the subtropical pine tip moth (Rhyacionia subtropica) and Nantucket pine tip moth (Rhyacionia frustrana). The moths are reddish copper in color, small (1/2” wingspan and 1/4” body length) and active at night. Caterpillar larvae have black heads and start out with off-white bodies, but change in color to brown and orange as they age.
While this insect activity typically does not kill the tree, it does cause some die-off of terminal needles and branches. In extreme cases, it can cause tree death. Moths prefer younger trees and rarely affect pines taller than 15 feet.
If you see a cluster of dead needles at the ends of young pine branches of your property, you can easily snap off the dead tip. You will likely find the hollow space formed by the larvae, which in spring may still contain the insect. Treatment in a home landscape can managed by hand removal of infested shoots, but those in the commercial forestry business may need to install traps and consider insecticidal management.
Visit the UF School of Forest Resources and Conservation website for more information.
by Mark Tancig | Mar 26, 2018
How many times have you pulled up to an intersection and couldn’t see oncoming traffic because a shrub was in the way? It’s frustrating, and unsafe. To help each other out, we should all pay attention to landscape plants that may be blocking the view of oncoming traffic and/or pedestrians, including your own driveway. Keeping a clear sight distance doesn’t mean you need a moonscape, but proper planning and maintenance of the landscape can look good and keep a clear sight distance.
“Site distance” is what traffic engineers call being able to see driving lanes and sidewalks, in both directions. I knew engineers had such a term and assumed they would have a precise way to measure it. Of course, since they’re engineers, they did. A local traffic engineer with the Leon County Public Works Department sent me the sketch. The figure should help, but, basically, you need to think of it as a sight triangles. The three points in each triangle are 1) the driver’s location at an intersection stop (where triangles meet), 2) the centerline of each lane, and 3) a point 300 – 500 down each lane. To determine if the view is clear, stand where a driver would stop, and approximate the height of the driver’s eye.
Please be safe as you rush to measure!
I can’t see if anyone’s coming! Credit: Mark Tancig/UF IFAS.
If you have vegetation in the way, assess the situation. First thing to determine is what plant(s) you have. If you don’t know, send a photo to your local Extension Office. Next, determine if the identified plant(s) can be pruned to get out of view and/or below the height of the driver’s eye. Transplanting to another location is a possibility, if it’s a plant that transplants well and isn’t too large. Otherwise, removing and replacing is the best option for the safety of the community.
When needing a low-growing replacement, consider the following Florida-Friendly plants:
African Iris (Dietes vegata) – Part Sun/Shade
Black-eyed Susan (Rudbeckia spp.) – Sun
Blue-eyed grass (Sisyrinchium angustifolium) – Part Sun/Shade
Butterweed (Packera glabella) – Shade
Coontie (Zamia florida) – Sun – Shade
Lily of the Nile (Agapanthus orientalis) – Part Sun/Shade
There are many, many more plants to choose from, including dwarf varieties of common ornamental plants. Your local Extension Office can help provide resources to help you make a good choice. Online resources, such as the Florida-Friendly Landscaping Pattern Books and the Guide to Plant Selection and Landscape Design, are also available.
by Carrie Stevenson | Mar 13, 2018
The swollen base and smooth gray bark of the swamp blackgum are identifying characteristics in wetlands. Photo credit: Carrie Stevenson, UF IFAS Extension
In the river swamps of northwest Florida, the first tree to come to mind is typically the cypress. The “knees” protruding from the water are eye-catching and somewhat mysterious. Sweet bay magnolia is an easily recognizable species as well, with its silvery leaves twisting in the wind. The sweet bay (Magnolia virginiana) is a relative of the Southern magnolia (Magnolia grandiflora) in many of our yards, but its buds and leaves are smaller and it is found most often in very wet soils.
However, the often-unsung trees of the swamps are the tupelo and blackgum trees, including three species of Nyssa that go by a variety of overlapping common names. In the western Panhandle, one is most likely to see a swamp tupelo/swamp blackgum (Nyssa sylvatica var. biflora). The trees are tall—60-100’ at maturity—and have unremarkable elliptical green leaves. However, those leaves turn a lovely shade of red in the fall before dropping in the winter. Their most distinguishing characteristic year-round–but especially in the winter–is its swollen lower trunk, which expands at the base to twice or three times the size of the remaining trunk. These buttresses, also found on bays (more subtly) and cypress (along with knees), are an adaptation to stabilizing a tree growing in large pools of wet, loose soil or standing water.
A young blackgum tree in full fall color. Photo credit: UF IFAS Extension
The swamp tupelo has two more relatives in the region, water tupelo (Nyssa aquatica) and Ogeechee lime/tupelo (Nyssa ogeche), both with hanging edible (but tart) fruit. In the early days of William Bartram’s explorations of Florida, explorers used the acidic Ogeechee lime as a citrus substitute. Typically found in a narrower range from Leon County east to southeast Georgia, the Ogeechee lime is the nectar source for the famous and prized multi-million dollar tupelo honey industry.
Blackgum or tupelo trees (missing the “swamp” in front of their common name—aka Nyssa sylvatica) are actually excellent landscape trees that can thrive in home landscapes. Like their swamp cousins, the trees perform well in slightly acidic and moist soil, although they can thrive even in the disturbed, clay-based soils found in many residential developments. Blackgums can grow in full sun or shade, are highly drought tolerant, and can even handle some salt exposure. Their showy fall color is a nice addition to many landscapes, and the fruit are an excellent source of nutrition for native wildlife.
by Sheila Dunning | Feb 5, 2018
Pruning is one of the most controversial aspects of maintaining crapemyrtle. Traditionally, many crapemyrtles are routinely topped, leaving large branch and stem stubs. This practice has been called “crape murder” because of the potential impacts on the crapemyrtle health and structural integrity. Topping is the drastic removal of large-diameter wood (typically several years old), with the end result of shortening all stems and branches.
Hard pruning (topping) stimulates crapemyrtle sprouting from roots, upper stems, or the base of main stems. If basal and root sprouts are not removed, one or more may form woody stems that eventually compete with existing main stems. These additional or competing stems may result in poor form and structure, such as stems that rub against each other.
Topping typically delays flowering up to one month compared to unpruned crapemyrtle. On some cultivars, topping also shorten the season of bloom. Long-stem sprouts emerge just below large-diameter cuts that result from topping. These sprouts usually develop into upright, unbranched stems that eventually flower, often bending under their own weight. Rain or wind storms can cause extreme bending and some will break because they are weakly attached to the main stem.
Topping removes large amounts of starches and other food reserves stored within branches. Topping dramatically reduces the size of the plant canopy, ultimately decreasing the plant’s ability to produce food (starches) through photosynthesis. The large branch stubs caused by topping result in large areas of exposed wood that allow access by insects and wood-rotting organisms, weakening the plant’s structure. Finally, topping results in many dead stubs throughout the tree.
Proper pruning may be needed, just like any other tree. Lower limbs of crapemyrtle are removed to increase clearance for pedestrians or vehicles. Stems are cut to increase branching. Other pruning may be conducted to direct growth away from structures, stimulate flowering, and remove spent flowers, seed capsules, and dead or damaged branches and twigs.
Properly placed, crapemyrtle is a low-maintenance plant needing little or no pruning. Problems with overgrown, misshapen, or misplaced crapemyrtle can be greatly reduced with proper selection of crapemyrtle cultivars, proper plant selection at the nursery, and proper placement in the landscape. For more information on cultivar selection go to: http://edis.ifas.ufl.edu/mg266.
If pruning is necessary, use the following recommendations:
- Pruning for safety may be done anytime. This may involve removing damaged or weak branches or pruning lower limbs for pedestrian and vehicle clearance and visibility.
- Pruning to improve plant structure, redirect growth, or alter plant shape and appearance should occur when plants are leafless and dormant–typically December through February. Although this can be accomplished at any time, without leaves, the branching structure is clearly visible to more easily determine appropriate branches for pruning.
- Prune to remove crossing or rubbing branches.
- Prune dead, damaged, or diseased branches at the branch collar.
- Remove vigorous branches growing toward the center of the canopy.
- Severe pruning should be performed late in the dormant period. Pruning too early might stimulate new growth that could be damaged by low temperatures.
by Carrie Stevenson | Jan 25, 2018
Ghost plant/Indian pipes emerging from the ground. Photo credit: Carol Lord, UF IFAS Extension
Imagine you are enjoying perfect fall weather on a hike with your family, when suddenly you come upon a ghost. Translucent white, small and creeping out of the ground behind a tree, you stop and look closer to figure out what it is you’ve just seen. In such an environment, the “ghost” you might come across is the perennial wildflower known as the ghost plant (Monotropa uniflora, also known as Indian pipe). Maybe it’s not the same spirit from the creepy story during last night’s campfire, but it’s quite unexpected, nonetheless. The plant is an unusual shade of white because it does not photosynthesize like most plants, and therefore does not create cholorophyll needed for green leaves.
In deeply shaded forests, a thick layer of fallen leaves, dead branches, and even decaying animals forms a thick mulch around tree bases. This humus layer is warm and holds moisture, creating the perfect environment for mushrooms and other fungi to grow. Because there is very little sunlight filtering down to the forest floor, the ghost flower plant adapted to this shady, wet environment by parasitizing the fungi growing in the woods. Ghost plants and their close relatives are known as mycotrophs (myco: fungus, troph: feeding).
Ghost plant in bloom at Naval Live Oaks reservation in Gulf Breeze, Florida. Photo credit: Shelley W. Johnson
These plants were once called saprophytes (sapro: rotten, phyte: plant), with the assumption that they fed directly on decaying matter in the same way as fungi. They even look like mushrooms when emerging from the soil. However, research has shown the relationship is much more complex. While many trees have symbiotic relationships with fungi living among their root systems, the mycotrophs actually capitalize on that relationship, tapping into in the flow of carbon between trees and fungi and taking their nutrients.
Mycotrophs grow throughout the United States except in the southwest and Rockies, although they are a somewhat rare find. The ghost plant is mostly a translucent shade of white, but has some pale pink and black spots. The flower points down when it emerges (looking like its “pipe” nickname) but opens up and releases seed as it matures. They are usually found in a cluster of several blooms.
The next time you explore the forests around you, look down—you just might see a ghost!
by Daniel J. Leonard | Jan 10, 2018
Are you guilty of “Crape Murder”, the dreaded horticultural sin that involves lopping off your beautiful Crape Myrtles fence post high and creating gnarly looking knuckles? No need to raise hands, you know who you are! Despite the cruelness of this act, all is not lost; there is still time to repent and change your ways! The facts of the matter are, if you have made a habit of lopping the tops off your crapes, you are most definitely not alone, you probably thought you were doing the right thing, and it can be corrected.
Improper pruning of crape myrtles. Photo Courtesy – Beth Bolles.
Crape Myrtle (Lagerstroemia spp.) are one of the most beautiful trees Southerners have in their horticultural arsenal. Unsurpassed in both form and flower, it is easy to see why Crape Myrtle is the most widely planted tree in the Southeastern United States. A mature Crape Myrtle properly grown is a remarkable sight, sinewy limbs reaching high in a vase shape supporting lilac-like flowers that come in a rainbow of colors. These qualities make it even more strange that homeowners and landscape professionals alike insist on butchering them every winter.
Before we move on to corrective procedures, let us examine a few of the reasons that crape murder is committed. First, I think peer pressure has a lot to do with it. When one sees every house on the street and all the business landscapes doing things a certain way, one tends to think that is the correct way. Second, there are folks who believe that pruning their crapes back each year creates a superior flower show. In reality, this practice creates an overabundance of succulent, weak, whippy branches (with admittedly larger flowers) that tend to bend over and break after a summer wind or rainstorm and are more prone to pests and disease. In addition, many homeowners over prune their crapes in this way because they planted a cultivar that grows too large for the site. There are dozens of crape myrtle cultivars sold, be mindful to pick one with a mature size and shape that will fit with the scale of the site!
So, now that we know why crape murder is committed, let’s discuss how to remedy it once the atrocity has already occurred.
- If the improper pruning has not been going on very long (a couple of years or less), it may be possible to correct over time without taking drastic measures. If this is the case, select two or three of the young “whippy” canes that are growing up and out and remove the rest. Ideally, the canes you select will be growing away from the center of the plant and not back into the middle of the plant or straight up to facilitate proper branch spacing as the tree continues to grow. The canes you select now will become primary branches in the years to come, so plan and prune carefully. Repeat for each main trunk that has been “murdered”. You will have to keep watch on the cut areas, as they will attempt to regrow as suckers after pruning; simply remove these juvenile shoots until they stop emerging.
Properly pruned crape myrtle. Photo courtesy – North Carolina Cooperative Extension
- If the murder has been going on for more than a year or two, it likely cannot be corrected without a major rejuvenation of the plant. Though it will likely be painful for you emotionally and seemingly run counterintuitive to your instincts, the best method to rejuvenate a disfigured crape is to break out the chainsaw and cut the plant back to the ground! This forces the plant to do one of two things; either grow an outrageous number of new shoots or die. In most cases however, the crape myrtle’s tough constitution permits it to regrow from the stump. The first growing season after performing this procedure, allow the shoots that sprout to grow and do not prune. The winter following the first growing season, remove all except three to five strong, well-spaced shoots and allow these to become the new plant’s main trunks. In all succeeding years, only prune to remove dead wood, crossing branches and branches growing toward the center of the plant.
If you have been guilty of crape murder, it is not too late to change your ways! Follow these steps, get out and enjoy the cool weather, and get to correcting your mistakes while the plants are still dormant! As always, if you have any questions about the topic of this article or any other horticultural topics, please contact your local Extension office and happy gardening!
