With spring upon us, the mighty monarch butterflies have begun their long trek to the north from Mexico, looking to time their migration with growth of the milkweed plants in the southeastern United States. Mated monarch females lay hundreds of eggs along their journey, but only two percent of these eggs will survive to become mature caterpillars to carry on the next generation.
The monarch butterfly.
Photo: Steven Katovich USDA Forest Service
Monarch larvae rely exclusively on milkweed for nutrients, so it is of upmost importance that the plants are available to the offspring at the correct time. If the adult monarchs arrive too early, the milkweeds may not have had enough time to grow after late frosts. If they arrive too late, the milkweed vegetation may not support the nutrient needs of the caterpillars. In addition, the milkweeds contain a poisonous toxin, cardiac glycoside, that stays within the caterpillars’ bodies once consumed. This does not harm the larvae, but actually helps them, as it makes the young and adult butterflies taste terrible and makes them poisonous to potential predators.
For these reasons, it is important that we all do our part to support the growth of native milkweed species. Locally, the Monarch Milkweed Initiate at the St. Marks National Wildlife Refuge educates the public about milkweed and monarchs and grows and transplants native milkweed to support the monarchs on their migration.
When planting milkweed, be aware that there is a popular commercialized non-native tropical milkweed species that is not appropriate for the monarchs in our area. This species, Asclepias curassavica, can flower year-round, luring the monarchs to stay and breed in the winter when they should be on their way back to Mexico to escape freezing temperatures. Staying and breeding too long can make the monarchs susceptible to a protozoan parasite, Ophryocystis elektroscirrha (OE for short), that infects the caterpillars when feeding, reducing their lifespan, body mass, mating success rate, and ability to migrate.
Butterfly milkweed (Asclepias tuberosa)
Photo: John Ruter, University of Georgia
Swamp milkweed (Asclepias incarnata).
Photo: David Cappaert
Luckily, there are about 21 native milkweed species in Florida. Many native milkweeds in the Florida Panhandle require specialized care when grown for transplanting, as different species have adapted to a range of habitats. The Asclepias tuberosa, commonly referred to as butterflyweed, is considered easiest to grow as they transplant well and thrive in full sun. Others, such as Asclepias perennis, or aquatic milkweed, and Asclepias incarnata, swamp milkweed, must be grown using trays without drain holes, as their “feet” must be kept wet. The Asclepias humistrata, or sandhill milkweed, requires a drier, heavier soil.
Monarch catepillar (Danaus plexippus).
Photo: Steven Katovich, USDA Forest Service
To support the monarchs and grow milkweed in your garden, come to the Leon County Extension Office at 615 Paul Russell Road on Saturday, May 11, from 9:00 a.m. to 1:00 p.m. for the Spring Open House and Plant Sale. Master Gardeners have been busy growing native milkweeds for this event and will be on hand selling the transplants. There will also be many other Florida Friendly and native plants available, along with guided garden tours, kids’ activities, the UF/IFAS Bookstore, a silent auction, live music by the Tallahassee Woodwind Quintet, refreshments, and Master Gardeners and Extension Agents on-hand to answer any of your gardening questions.
Young Longleaf Pine
All of Florida’s ecosystems contain pine trees. There are seven native species in the state; Sand, Slash, Spruce, Shortleaf, Loblolly, Longleaf, and Pond. Each species grows best in its particular environment. Pines are highly important to wildlife habitats as food and shelter. Several species are equally valuable to Florida’s economy. Slash, Loblolly, and Longleaf are cultivated and managed to provide useful products such as paper, industrial chemicals, and lumber. All pines are evergreens, meaning they keep foliage year-round. The leaves emerge from the axil of each scale leaf into long slender needles clustered together in bundles. Needles are produced at the growing tips of each branch and remain on the tree for several years before turning reddish-brown and falling off. The bundles are referred to as “fascicles”. The length and number of needles in each fascicle is one way to help identify the different pine species.
A handy rule of thumb is that pines starting with “S” have needles in twos, while pines starting with “L” have needles in threes. And slash pine, which starts with “SL” has needles in twos and threes. The pond pine is also a three-needled fascicle. Pay attention to their length and the number that are held in a fascicle. Because the numbers per fascicle may vary, be sure to check several fascicles to get an overall sense for the plant! Longleaf has the longest needle, measuring over 10 inches. While sand pine has the shortest needles at around 2 inches in length. Pine cones are also a means for identification. Typically the longer the needle, the bigger the cone. But, they also vary in attachment and “spinyness’.
Cone of Loblolly Pine, attached directly to the stem
The outer (dorsal) surface of each seed cone scale has a diamond-shaped bulge, or “umbo,” formed by the first year’s growth. The umbo may or may not be armored with a “prickle,” a sharp point but not quite a spine or thorn, at the tip. As the seed cone continues to grow and expand, the exposed area at the end of each scale grows as well. The larger diamond-shaped area around the umbo, formed in the second year of growth, is called the “apophysis.” The shapes of the prickle, umbo, and apophysis can be helpful in identification. The male and female cones are separate structures, but both are present on the same plant. Pollen is produced by male cones and is carried by the wind to female cones where it fertilizes the ovules. Seeds develop and mature inside the female cones (also called the seed cones) for two years, protected by a series of tightly overlapping woody scales. Some pines open their seed cones after two years to release the seeds, while other pines continue to keep their cones tightly closed past maturity and release seeds in response to the heat of a forest fire.
To learn more about Florida’s pines and helpful hint on identification go to:
Tree planting in Mary Esther
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 most 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.
Trees provide us with benefits including serving as a sound barrier, stormwater abatement, and of course fresh air and oxygen
“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.”
~Theodore Roosevelt, 1907 Arbor Day Message
Throughout history the evergreen tree has been a symbol of life. “Not only green when summer’s here, but also when it’s cold and dreary” as the Christmas carol “O Tannenbaum” says. After such devastating tree losses in the Panhandle this year, this winter is a prime time for installing more native evergreens.
While supporting the cut Christmas tree industry does create jobs and puts money into local economics, every few years considering adding to the urban forest by purchasing a living tree. Native evergreen trees such as Redcedar make a nice Christmas tree that can be planted following the holidays. The dense growth and attractive foliage make Redcedar a favorite for windbreaks, screens and wildlife cover. The heavy berry production provides a favorite food source for migrating Cedar Waxwing birds. Its high salt-tolerance makes it ideal for coastal locations. Their natural pyramidal-shape creates the traditional Christmas tree form, but can be easily pruned as a street tree.
Two species, Juniperus virginiana and Juniperus silicicola are native to Northwest Florida. Many botanists do not separate the two, but as they mature, Juniperus silicicola takes on a softer, more informal look. For those interested in creating a different look, maybe a Holly (Ilex,sp.) or Magnolia with full-to-the-ground branches could be your Christmas tree.
When planning for using a live Christmas tree there are a few things to consider. The tree needs sunlight, so restrict its inside time to less than a week. Make sure there is a catch basin for water under the tree, but never allow water to remain in the tray and don’t add fertilizer. Locate your tree in the coolest part of the room and away from heating ducts and fireplaces. After Christmas, install the new tree in an open, sunny part of the yard. After a few years you will be able to admire the living fence with all the wonderful memories of many years of holiday celebrations. Don’t forget to watch for the Cedar Waxwings in the Redcedar.
As the trees begin to turn various shades of red, many people begin to inquire about the Popcorn trees. While their autumn coloration is one of the reasons they were introduced to the Florida environment, it took years for us to realize what a menace Popcorn trees have become. Triadica sebifera, the Chinese tallowtree or Popcorn tree, was introduced to Charleston, South Carolina in the late 1700s for oil production and use in making candles, earning it another common name, the Candleberry tree. Since then, it has spread to every coastal state from North Carolina to Texas, and inland to Arkansas. In Florida it occurs as far south as Tampa. It is most likely to spread to wildlands adjacent to or downstream from areas landscaped with Triadica sebifera, displacing other native plant species in those habitats. Therefore, Chinese tallowtree was listed as a noxious weed by the Florida Department of Agriculture and Consumer Services Noxious Weed List (5b-57.007 FAC) in 1998, which means that possession with the intent to sell, transport, or plant is illegal in the state of Florida. The common name of Florida Aspen is sometimes used to market Popcorn tree in mail-order ads. Remember it’s still the same plant.
Although Florida is not known for the brilliant fall color enjoyed by other northern and western states, we do have a number of trees that provide some fall color for our North Florida landscapes. Red maple, Acer rubrum, provides brilliant red, orange and sometimes yellow leaves. The native Florida maple, Acer floridum, displays a combination of bright yellow and orange color during fall. And there are many Trident and Japanese maples that provide striking fall color. Another excellent native tree is Blackgum, Nyssa sylvatica. This tree is a little slow in its growth rate but can eventually grow to seventy-five feet in height. It provides the earliest show of red to deep purple fall foliage. Others include Persimmon, Diospyros virginiana, Sumac, Rhus spp. and Sweetgum, Liquidambar styraciflua. In cultivated trees that pose no threat to native ecosystems, Crape myrtle, Lagerstroemia spp. offers varying degrees of orange, red and yellow in its leaves before they fall. There are many cultivars – some that grow several feet to others that reach nearly thirty feet in height. Also, Chinese pistache, Pistacia chinensis, can deliver a brilliant orange display.
Young Trident maple with fall foliage. Photo credit: Larry Williams
There are a number of dependable oaks for fall color, too. Shumardi, Southern Red and Turkey are a few to consider. These oaks have dark green deeply lobed leaves during summer turning vivid red to orange in fall. Turkey oak holds onto its leaves all winter as they turn to brown and are pushed off by new spring growth. Our native Yellow poplar, Liriodendron tulipifera, and hickories, Carya spp., provide bright yellow fall foliage. And it’s difficult to find a more crisp yellow than fallen Ginkgo, Ginkgo biloba, leaves. These trees represent just a few choices for fall color. Including one or several of these trees in your landscape, rather than allowing the Popcorn trees to grow, will enhance the season while protecting the ecosystem from invasive plant pests.
For more information on Chinese tallowtree, removal techniques and native alternative trees go to: http://edis.ifas.ufl.edu/ag148.
Lantana, on the left, and Mexican Petunia, on the right, are both exotic invasive plants which can displace many native species and disrupt the natural balance.
Autumn is usually considered the season of colors in the natural parts of north Florida, and other locations in North America. This tonal attribute is commonly credited to the foliage changes as the growing season ends.
Maples, sweet gums, hickory and many others make their contributions to the natural palette of shades and hues which have existed since long before human habitation in the area. Even some of the native plants add to the display.
Goldenrod and dogfennel add highlights to the brilliant display as winter, believe it or not, approaches. Unfortunately there are some attractive shades in the exhibition which are an indication of exotic invasive plants which have pushed out native.
Both lantana and Mexican petunias are currently blooming, but an indication of problem species. Both were introduces as ornamental plants, but quickly escaped into the wild where they could colonize unchecked.
Lantana (Lantana camara) is a woody shrub native to tropical zones of North and South America. It flowers profusely throughout much of the growing season.
Because of the plant’s ornamental nature, many different flower colors exist, but the most frequent color combinations are red and yellow along with purple and white. Lantana is now commonly found in naturalized populations throughout the southeastern United States from Florida to Texas.
It is currently ranked as one of the top ten most troublesome weeds in Florida and has documented occurrences in 58 of 67 counties. Curiously, despite the bad reputation it is still found in home and commercial landscapes.
As part of its arsenal of conquest, Lantana produces allelochemicals, or plant toxins, in its roots and stems. These allelochemicals have been shown to either slow the growth of other plants or totally remove them.
Some of these same chemicals give lantana an acrid taste and deter insects or other animals from consuming the leaves. Of importance to pet and livestock owners, these leaf toxins are damaging to animals.
If animals consume the leaves, they often begin to show symptoms of skin peeling or cracking. Once animals show these symptoms, there is little or no treatment that can reverse the process.
Although lantana’s leaves are poisonous, its berries are not. Birds readily consume the fruit and are responsible for much of the seed’s distribution over wide areas.
Mexican petunia (Ruellia simplex) is a native of Mexico, but also the Antilles and parts of South America. Its tolerance of varying landscape conditions makes it a common choice for difficult to plant areas and has contributed to it popularity and wide use.
Mexican petunia tolerates shade, sun, wet, dry, and poor soil conditions. It is a prolific bloomer with flowers in shades of purple and pink peaking in the summer, but with the potential to also bloom in spring and fall in some parts of Florida.
Environmental tolerance, abundant seed production, and an ability to easily grow from plant cuttings have all promoted the spread into natural areas bordering developments. The Mexican petunia has been credited with “altering native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives” according to the Florida Exotic Pest Plant Council in 2011.
Given the continued popularity of both species, plant breeders have developed sterile, non-reproducing cultivars which do not have the negative characteristics of these problem plants. It is recommended using only the sterile type so autumn’s colors continue to be natural.
To learn more about north Florida’s colorful invasive plants, contact the local UF/IFAS County Extension Office. Click here for contact information.