Fences make good neighbors except when your neighbor is a Chinese tallow or popcorn tree. Seed is easily spread across property borders. Birds, storm-water, and vehicles are just few ways seeds move away from large trees. Photo by Scott Jackson.
Benjamin Franklin has been blamed for introducing the invasive Chinese Tallow tree to the Southeast when he mailed seeds to a planter after one of his trips to London in the late 1700’s. However, recent DNA work has traced the invasive strain to federal scientists’ importations in 1905.
No matter. The “Popcorn Tree,” as it’s also called because of its white seeds, has invaded the Gulf coast from Texas to Florida, especially the wetlands and bottomland forests. A mature tree may produce as many as 100,000 seeds annually. These seeds can be spread by birds or moving water and expedite the trees’ takeover of habitat. The sap and berries are toxic to humans and livestock. It has been planted for its red fall color, but it crowds out native wetland species such as black gum and red maple, both noted for their red fall leaves. Its tolerance to flooding and saltwater can also make it a threat to bald cypress.
Recently research by scientists of the US Forest Service and others has shown the dissolved oxygen and pH levels in the leaf litter of the tallow tree are fatal to the early stage eggs of the leopard frog. While tallow trees provide a nectar source for bees and have been investigated as a biofuel source, the damage to wetlands caused by these invaders more than offsets the positive aspects of the plant.
Small seedlings may be hand pulled, especially in wet areas, but care should be taken to leave no root pieces to resprout. Herbicides including triclopyr can control Chinese Tallow. More information is available at http://edis.ifas.ufl.edu/ag148 and http://plants.ifas.ufl.edu/node/676.
For local assistance, contact your county UF IFAS Extension office.
Coral ardisia is also known as coral berry, spice berry, and scratchthroat. It was introduced into Florida in the early 1900’s for ornamental purposes.
In the ensuing years it has since escaped cultivation and become established in hardwood hammocks and other moist woods of natural areas and grazing lands. Specimens have been collected from 19 western and south-central Florida counties as of 2004.
This evergreen sub-shrub reaches a height of 1.5 to six feet and tends to grow in multi-stemmed clumps. Leaves are alternate, 8 inches long, dark green above, waxy, without hairs, and have scalloped margins and calluses in the margin notches.
Flowers are typically pink to white in stalked axillary clusters, usually drooping below the foliage. The fruit is a bright red, globose, single-seeded berry, measuring approximately 0.25 inches in diameter. White-berried populations are also known to exist.
Coral ardisia is considered invasive. Control of coral ardisia may be accomplished by two methods. A low-volume foliar application of Garlon 4 or Remedy provides suppression of this plant. Complete foliar coverage is essential to success and retreatment will be necessary for complete control.
Basal bark applications with Garlon 4 or Remedy in an oil carrier can also be utilized for suppressing this invasive weed. Do not apply more than 8 quarts of Remedy or Garlon 4 per acre and treat no more than ten percent of the total grazed area if applying greater than two quarts per acre.
For more information contact your local UF/IFAS Extension Office and read the following publication: http://edis.ifas.ufl.edu/ag281
The best time to plant a tree is twenty years ago. The second best time is for Arbor Day. Florida recognizes the event on the third Friday in January, but planting any time before spring will establish a tree quickly.
Arbor Day is an annual observance that celebrates the role of trees in our lives and promotes tree planting and care. As a formal holiday, it was first observed on April 10, 1872 in the state of Nebraska. Today, every state and many countries join in the recognition of trees impact on people and the environment.
Trees are the longest living organisms on the planet and one of the earth’s greatest natural resources. They keep our air supply clean, reduce noise pollution, improve water quality, help prevent erosion, provide food and building materials, create shade, and help make our landscapes look beautiful. A single tree produces approximately 260 pounds of oxygen per year. That means two mature trees can supply enough oxygen annually to support a family of four.
The idea for Arbor Day in the U.S. began with Julius Sterling Morton. In 1854 he moved from Detroit to the area that is now the state of Nebraska. J. Sterling Morton was a journalist and nature lover who noticed that there were virtually no trees in Nebraska. He wrote and spoke about environmental stewardship and encouraged everyone to plant trees. Morton emphasized that trees were needed to act as windbreaks, to stabilize the soil, to provide shade, as well as, fuel and building materials for the early pioneers to prosper in the developing state.
In 1872, The State Board of Agriculture accepted a resolution by J. Sterling Morton “to set aside one day to plant trees, both forest and fruit.” On April 10, 1872 one million trees were planted in Nebraska in honor of the first Arbor Day. Shortly after the 1872 observance, several other states passed legislation to observe Arbor Day. By 1920, 45 states and territories celebrated Arbor Day. Richard Nixon proclaimed the last Friday in April as National Arbor Day during his presidency in 1970.
Today, all 50 states in the U.S. have official Arbor Day, usually at a time of year that has the correct climatological conditions for planting trees. For Florida, the ideal tree planting time is January, so Florida’s Arbor Day is celebrated on the third Friday of the month. Similar events are observed throughout the world. In Israel it is the Tu B Shevat (New Year for Trees). Germany has Tag des Baumes . Japan and Korea celebrate an entire week in April. Even, Iceland one of the treeless countries in the world observes Student’s Afforestation Day.
The trees planted on Arbor Day show a concern for future generations. The simple act of planting a tree represents a belief that the tree will grow and some day provide wood products, wildlife habitat erosion control, shelter from wind and sun, beauty, and inspiration for ourselves and our children.
“It is well that you should celebrate your Arbor Day thoughtfully, for within your lifetime the nation’s need of trees will become serious. We of an older generation can get along with what we have, though with growing hardship; but in your full manhood and womanhood you will want what nature once so bountifully supplied and man so thoughtlessly destroyed; and because of that want you will reproach us, not for what we have used, but for what we have wasted.”
Anyone who has had a treasured palm tree annihilated by palmetto weevils (Rhynchophorus cruentatus) knows the pain of losing a long-lived tree from the home landscape. These large, native weevils are adept at working unnoticed inside a palm to the point of terminal damage. Typically, by the time you notice that the tree is declining and fronds begin to turn brown there is likely no hope of salvaging the situation. By then the larval grubs have already damaged the tree’s growing bud to the point of no return. At this stage the recommended procedure involves removing the tree, cutting it up and burning it to prevent the invading long-snouted critters from moving over to neighboring palms.
Color and size of adults is quite variable.
However, as frustrating as this is, if we step back and look at the bigger picture it is apparent that even our most aggravating native insect pests are part of the natural web of life and local plants have adapted to survive these “give and take” relationships on the population scale.
Palmetto weevils establish in a new tree when adult females lay their eggs in the crown of the tree and larvae hatch to burrow into the soft terminal bud. It is larval feeding that does the lethal damage. Larvae are large, white, legless grubs that can reach lengths of six-seven centimeters. When larvae are mature they create a cocoon inside the tree from tree fibers and pupate there before hatching into adults to start the cycle over. Grubs can be found in any part of the tree but really need the softer, growing parts for food, such as in the base of the living fronds and the terminal bud.
Weevil damage at base of frond.
The condition created by these burrowers is often referred to as “popped neck,” where the top of a palm tree dies and caves over. If you are in the process of removing a dying or dead palm due to the crown dying it would be a good idea cut through the top section with a chainsaw to see if weevil damage is evident in large (about ½ inch) diameter tunnels. If a live specimen of an adult can be captured in a jar it would be worth a visit to your local Extension office for a positive identification to make sure you aren’t dealing with another similar species of non-native weevil that has not been documented in Florida yet. The red palm weevil (Rhynchophorus ferrugineus) has now been found in the U.S. at Laguna Beach, California. Coloration varies by individual bug but a positive i.d. can be obtained by sending the specimen to UF’s laboratory in Gainesville. For further information on palmetto weevils refer to the EDIS fact sheet at this web link.
Dodder vines covering an oak seedling. The vines always wrap counterclockwise. Photo Credit: Jed Dillard
Vampires of all types and genetic modifications are hot topics these days, and a common, but uncommon looking and acting Florida weed may have combined the two subjects. Dodder, a native invasive, parasitic plant, reproduces by seed but does not have enough leaves or chlorophyll to feed itself. Its thin, golden vines and tendrils must attach to a host plant in the seven to ten days it takes the plant to exhaust the carbohydrates in its small seed. Once dodder attaches to a plant, it connects to the inside of the host using small structures called haustoria which press into the stem and begin to draw nutrients from the host. At this point the dodder roots atrophy.
Single dodder plants are not a big issue, but once enough plants build up in an area large mats of vines can reduce growth and vitality of the host. (See photo) Frequently, the pest has reached this stage before it’s noticed, leaving the problem of treating a rootless, nearly leafless plant that is wrapped around a more desirable plant. Not only are the typical routes of herbicidal entry minimized, the hosts are at as much risk as the pest. Hand removal may be practical in small outbreaks, but the plant can reemerge from any small piece left attached to the host. In most cases, the solution is to destroy the host and the dodder and apply a pre-emergent herbicide to stop germination from any seeds remaining in the soil.
What about the GMO angle?
Work published last year in the journal Science by Jim Westwood of Virginia Tech reveals the dodder plant exchanges messenger RNA with tomato and Arabidopsis plants when it extracts the juices from the host plant. Scientists speculate this exchange of genetic material makes the host plant less resistant to attack by the parasite and that this holds promise for learning more about controlling other parasitic plants.
If plants are exchanging messenger RNA, a critical part of protein and gene synthesis, what other genetic exchanges are occurring naturally without our knowledge? Scientific progress hinges on unpredictable events and sources. Learning more from a “vampire weed” that has no easy means of control may be one of those.
To see the dodder plant go from seed to golden mat, watch this time lapse video Virginia Tech has posted on Vimeo. http://www.vtnews.vt.edu/articles/2014/08/081514-cals-talkingplants.html
Monitor your ponds closely throughout the spring and make any necessary herbicide applications before weed growth becomes too excessive. Photo Credit: Mark Mauldin
Similar to Goldilocks’ porridge, water temperature doesn’t need to be too hot or too cold, it needs to be just right for using aquatic herbicides (70o – 80o F). Here in Florida, these optimum water temperatures occur in the spring. Water temperature largely regulates the growth of most aquatic weeds; cool temperatures slow or stop growth and warm temperatures promote growth. Keeping this simple principle in mind can help determine when to use aquatic herbicides.
Generally speaking, aquatic herbicides are not used when water temperatures are below 60o F. When water temperatures are this cool most aquatic weeds are not actively growing. For herbicides to be effective the target plants must be actively growing. Applying herbicides too early in the spring is generally not an issue because winter dieback can make many aquatic weeds hard to find when water temperatures are cool. The weeds are out of sight and out of mind. The much more common issue is waiting too long before attempting to control weeds.
As water temperatures climb above 60o weeds begin to grow. Unfortunately, they often times grow unnoticed throughout the spring until they become completely out of control in the summer. By this point, control, even using herbicides, is a monumental task. If at all possible, control weeds early in the growing season.
As plants grow they are able to build up energy reserves, making them more difficult to control. The longer they are allowed to grow the stronger and more difficult to control they become. Controlling weeds earlier in the growing season eliminates this problem.
Similarly, as the growing season progresses plants produce more and more biomass. If an herbicide is applied and the weeds are killed large amounts of decomposing plant material in the water can cause problems. The decomposition process uses oxygen; dissolved oxygen can drop to levels that are hazardous to fish and other aquatic species. The more plant material that is present when herbicides are applied the bigger concern this becomes. Applying herbicides earlier in the growing season, before large amounts of biomass are produced, can help lessen this problem.
Aquatic weeds can grow rapidly when temperatures are warm. Don’t let them get out of control before you begin control efforts. Photo Credit: Mark Mauldin
Further compounding the issue, warm water is physically able to hold less dissolved oxygen than cooler water. Late in the summer pond water can be very warm with low concentrations of dissolved oxygen even before large amounts of decomposing plant material are added.
To help reduce the risk of oxygen depletion never treat more than ½ of a pond at one time, if weed growth is already substantial treat no more than 1/3 of a pond at one time and always allow 10 -14 days for oxygen recovery between treatments. Also, avoid treating on cloudy days, another factor that can lead to lowered dissolved oxygen.
Aquatic weed control will be easier and more effective if you monitor your pond throughout the spring and make any needed herbicide applications early, before the weeds have grown too large and the water is too warm. Consult your county extension agent for assistance determining what aquatic weeds you have and if treatment is necessary. Always read and follow all label directions when using any herbicide.
