Arbor Day 2015

Stinging caterpillars in our midst

When you think of caterpillars, you think of worm-like leaf-eaters that are generally harmless to humans.  Caterpillars may be hairless, fuzzy like a wooly bear or even tufted with hair – almost inviting you to touch them.  But there are “stinging” caterpillars in Florida that should not be touched.  To touch any of the four different kinds of stinging caterpillars found in Florida can become a painful experience.  Beware the Io moth caterpillar, the saddleback caterpillar, the puss caterpillar and the hag caterpillar.

Stinging caterpillars  have spines tipped with venom known as urticating spines.  Many people who touch these caterpillars experience itching or burning; others may have severe reactions that require medical attention.   Io moth caterpillars are brightly colored spiny larva.  These large (around two and one-half inches long) caterpillars are pale green with white and red stripes and seem to be the most common venomous caterpillar found in Charlotte County – I just saw three full-sized specimens last week.  Their spines are yellow with black tips that occur on fleshy bumps covering the body.  Io caterpillars may be found feeding on hibiscus, certain palms and Royal Poinciana, as well as a variety of other plants including wax myrtle.  The adult is a colorful and stunningly beautiful giant silk moth, yellow to orange in color, complete with eyespots on the hind wings..

In addition to the Io moth, Saddleback caterpillars also give clues that caution is required with  bright colors and bristly hairs.  This insect larva is brown with a green mid-section outlined in white.  A gap in the center of the back gives the entire pattern the appearance of a saddle.  The adult moth is small and drab and otherwise unremarkable.  Saddlebacks may be found on dozens of plants including  viburnum, Brazilian pepper, a variety of different palms, hollies, hibiscus and podocarpus.

Another strange venomous caterpillar is called the puss caterpillar which is also known as the southern flannel moth.  The adult orange moths are very fluffy and soft in appearance – the Persian cats of the moth world!  Up to one inch in length, the gray or brown caterpillars look like walking hair pieces totally covered in what appears to be soft hairs.  Scattered amongst the soft hairs are the urticating spines.  Severe pain can be the result of touching this caterpillar when the toxic spines break off in the skin.  The toxicity of the sting will tend to increase as the caterpillar grows – it is known as one of the most venomous caterpillars in the U.S.  Keep an eye out for them on oaks and elms. 

A final caterpillar to watch out for is the hag caterpillar.  These really look like trouble!  With curved and twisted projections covered with stinging hairs, hags speak volumes with their appearance  figuratively screaming, “DON’T TOUCH ME!”  While not as common as other stinging caterpillars, they may be found on various native and ornamental woody plants.

Many of these stinging caterpillars are plagued with natural enemies that keep them under control including parasitic wasps and flies.  If you are stung by these caterpillars, the literature suggests that placing common transparent tape over the affected area and striping off the irritating hairs that stick to the tape will help.  Applications of ice and a baking soda and water paste will help relieve the pain.  As mentioned earlier, if the person stung has allergies, asthma or allergic reactions, obtain medical help immediately.

For more information on all types of stinging creatures in our area, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer.  Don't forget to visit our other County Plant Clinics in the area.  Please check this link for a complete list of site locations, dates and times - http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.

Resources: 

Short, D.E., Habeck, D.H. & Castner, J .L. (2013) Stinging and Venomous Caterpillars.  The University of Florida Extension Service. IFAS.

Hall,  D. W. (2014) Io Moth Automeris io (Fabricius) (Insecta: Lepidoptera: Saturniidae). The University of Florida Extension Service. IFAS.

Hall,  D. W. (2013) Puss Caterpillar (Larva), Southern Flannel Moth (Adult), Megalopyge opercularis (J. E. Smith 1797) (Insecta: Lepidoptera: Zygaenoidea: Megalopygidae). The University of Florida Extension Service. IFAS.

Christopher S. Bibbs and J. Howard Frank

Nothing odder than a dodder

Have you ever heard of a plant called strangleweed, goldthread, devil’s-guts, or hellbine? How about dodder vine? This vampire-like plant is commonly called dodder vine and it is a genuine plant parasite. Golden yellow to orange in color, this vine has limited chlorophyll and cannot make sufficient food for itself. Because of this deficiency, dodder vines must function as parasites where they obtain nourishment from other plants. I saw a small patch of dodder vine beginning to grow the other day along the side of a road. Did it come from outer space or just from our backyard? Let’s take a closer look at this local plant.

The dodder vine starts from seed that came from a mother plant that has the potential of producing thousands of seeds in a season. If these seeds do not find a suitable environment in which to germinate, they have the ability to remain viable and dormant in the soil for many years.  However, once a dodder seed germinates, it has only a few days to find and attach to a host plant or it will die. As the seedling begins to grow it will move and reach out with its worm-like vining habit to hopefully latch onto a suitable host such as onions, peas, beans, potatoes, mums, ivies, petunias, and a multitude of native plants including the Virginia Creeper. Once a host is found, the dodder vine coils around its victim and presses disk-like organs onto and into the plant. This makes the connection to the host plant so that the dodder vine can extract the nutrients it needs to survive. Dodder vines are very eye-catching and worthy of further investigation. Several years ago I saw an infestation that was 10 feet wide and 30 feet long covering an undisturbed area of salt-bush. Imagine plants seemingly covered by a neon orange tangle of wiry, leafless vines!  Not only is dodder vine a parasite, but it is also known to spread various plant diseases.

What can you do if you have a dodder vine infestation? Keep in mind that dodder vine seeds can last for a long time and are spread by water, livestock manures, and old previously infested plant materials. There are no specific selective herbicides available to control this weed. Also, even if you used a non-selective herbicide, not only will the dodder vine be killed, but also the desirable plant as well. Your best bet is to hand pull the dodder and its infested host all at once. It is especially important that you destroy the dodder
vine before it sets seeds. The dodder vine can be a challenging pest to deal with and even a broken stem can find a new host. However, with some knowledge and skill you can defeat this parasite in your landscape. For more information on all types of plants in our area, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer.  Don't forget to visit our other County Plant Clinics in the area.  Please check this link for a complete list of site locations, dates and times - http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.

Resources:
Friday, F. (2001) Friday’s Feature – Dodder. Santa Rosa County UF/IFAS Extension Service.
Duever, L.C. (2004) Floridata – Cuscuta spp. Tallahassee, Florida.
Schalau, J. (2009) Dodder: A Plant Parasite.  The University of Arizona Cooperative Extension, Yavapai County.
Swift, C. (2010) Dodder. Colorado State University Cooperative Extension, Denver County.
Agriculture and Natural Resources, University of California. Dodder  (Cuscuta spp.) (2014)  http://www.ipm.ucdavis.edu/PMG/WEEDS/dodder.html

Is there a persimmon in your future?

Our 2015 Master Gardener Training class was getting a short lesson on different backyard fruits a couple of weeks ago.  One of those fruits was the persimmon.  While we have what is called the common or American  persimmon as a native tree here in Charlotte County, cultivated types brought from Asia in the mid 1800’s have far superior eating qualities.  Actually introduced by Commodore Perry in 1856, a good deal of work has been done since to evaluate cultivars.    A very uncommon fruit locally, persimmons are worth  a second look.

Originally from China, the persimmon is an under-used fruit tree that can grow here in Charlotte County in our 9b hardiness zone.  A deciduous tree growing no more than twenty-five feet in height, the persimmon produces orange conical to oblong fruit which are either considered astringent or non-astringent.  Astringent fruit, by their very nature, make your mouth feel dry and puckered to the taste until the fruit is fully ripe and soft.  Until that point,  the fruit is not suitable for eating.   Non-astringent types of persimmons produce fruit that can be eaten while still hard like an apple.  Additionally, some persimmons are seedless, while some have seeds, depending on the pollination situation, which can further affect the astringency and/or flavor.

Plant persimmon trees in well-drained soils in full sun sites.  After establishment, fertilize as you would a citrus tree with light fertilizations the first year.  After the first year, applications of fertilizer three times a year as per label instructions are sufficient.  Apply a mulch, (not right up against the tree), to suppress weeds and retain moisture.

What are best types for our area?  A persimmon named ‘Fuyu’ is perhaps the most popular non-astringent type in Florida.  It is so productive that thinning the fruit is often necessary.  The fruit is oblate in shape having a flattened, rounded form reminding you of a tomato at a glance. The fruit of  ‘Fuyu’  is generally ready to harvest from November to early December. The cultivar called ‘Tanenashi’, is a popular astringent cultivar recommended here in Florida for homeowners.  It can produce large crops of three and one-half inch yellow to orange  fruit  without any pollination.  The fruit is round and conical in shape.  Harvest the fruit from September to November. 

Cultivated persimmon trees are rarely available locally other than through specialty nurseries or family garden centers.  There are a few Internet nursery sources in Florida which you check out in any search engine.   We have one well-established persimmon that produced heavily last year.  The conical fruit (we are not sure of the cultivar) was sweet and very delicious.   With this success and other similar reports in Lee County, perhaps try a persimmon as an excellent dooryard tree this year.  For more information on all types of fruits trees suitable to grow in our area, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer.  Don't forget to visit our other County Plant Clinics in the area.  Please check this link for a complete list of site locations, dates and times - http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.

Resources:

California Rare Fruit Growers, Inc. (1996) Persimmon. 

E. P. Miller & T. E. Crocker (1994) Oriental Persimmons in Florida. The University of Florida Extension Service, IFAS.

Gilman, E. F. & Watson, D. G. (2014) Diospyros virginiana: Common Persimmon. The University of Florida Extension Service, IFAS.

Toxic plants aplenty

Plants are all around us and many of us  interact with them on a daily basis.   Some of these plants are noted to be toxic either by touch or ingestion.  Many of these plants are in our landscapes and some are used as houseplants.  Just knowing which plants are toxic is helpful to help you avoid or at least manage the risk.

As there are so many plants that can be toxic, and as some people may have individual allergic reactions not experienced by the general population,  only a few will be mentioned in this article.  The first set will be plants that have irritating sap which can cause problems to the skin.  One that comes to mind is the Pencil Cactus.   The Pencil Cactus is also called the  Milk Bush or Euphorbia tirucalli L..  The Pencil Cactus is a succulent, branching plant that can grow up to fifteen feet tall.   The sap is white in color and is extremely toxic and irritating  to the skin. It was even noted as being used as a fish poison in India.  Crown-of-thorns is another member of the Euphorbiaceae family that has milky, very irritating sap that can cause blisters.   There are several flowering shrubs in the genus Jatropha  (also in the Euphorbiaceae family) commonly found in many landscapes that have milky irritating sap and   toxic properties if consumed.  Look out for those Euphorbia’s!

Dieffenbachia is a common houseplant/patio plant with large colorful green and white patterned leaves emerging from a thick, central cane.  Also called "dumb cane", Dieffenbachia contains calcium oxalate, and if consumed,  produces irritation of the mucous membranes resulting in throat swelling and temporary loss of speech.  Almost everybody knows the flowering shrub Oleander.  Oleander is well known as toxic plant and all parts are considered poisonous if ingested. Even inhaling the smoke from burning oleander can cause poisoning.

Many gardeners plant lantana for their beautiful flowers that attract butterflies. The immature, green seeds of this plant are highly toxic, and the leaves are also highly toxic to animals. Even touching  lantana plants may cause skin irritation or allergic reactions in some people.

On occasion gardeners may grow ornamental selections of castor-beans.  Caster-beans contain a highly poisonous substance, ricin, as well as other toxic compounds.  The chemicals are more concentrated in the castor-bean seeds.  The Gloriosa Climbing lily is sometimes grown for its colorful and exotic–looking flowers.  The entire vining  plant contains toxic substances, and the underground tubers have the highest concentration. Death has been reported to occur within 4 hours after eating tubers of this plant.

In addition to the danger to humans, keep in mind that toxic plants can be an issue for pets and livestock.  As with any risk, use common sense, find out about the particular plants in your landscape and plant (plan) accordingly.  Precautions such as protective gloves and/or clothing may also help you avoid exposure if working with certain toxic plants.   If a human emergency occurs, contact resources such as the Florida Poison Information Center  at 1-800-222-1222, and/or your local Emergency Room.  Be smart and be careful!  For more information on all types of toxic plants, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer.  Don't forget to visit our other County Plant Clinics in the area.  Please check this link for a complete list of site locations, dates and times - http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.

Resources:

Purple Trailing Lantana (2007) The University of Florida Extension Service, IFAS - Baker County.
Florida Poison Information Center - http://www.poisoncentertampa.org/ .
Gardening in a Minute (2013) Lantana. The University of Florida Extension Service, IFAS.
Christman, S. (2003) Jatropha integerrima. Floridata.com , Tallahassee, FL.
Marshall, D. (2015) Poisonous Plants. The University of Florida Extension Service, IFAS - Monroe County Extension.
Feser, C. (2007) Poison plants. The University of Florida Extension Service, IFAS – Collier County.
Ferrer, A. (2015) poisonous plants in the garden. The University of Florida Extension Service, IFAS – Seminole County.
Scheper, J. (2004) Lantana montevidensis Floridata.com , Tallahassee, FL.
http://www.poisoncentertampa.org/ - Florida Poison Information Center.

If we only had a time machine

If we only had a time machine we could actually go back in time and stop the introduction of the Brazilian Pepper-tree into Florida in the mid-1800’s.  This classic invasive plant went from an introduced coveted ornamental, to the one of the worst and most successful invasive plants in the state of Florida.  Well, we live and we learn as the Brazilian Pepper-tree is here to stay.  But, we can push back and take care of our corner of Florida with a number of management options that will help suppress this dastardly poison-ivy relative.  How can we control the Brazilian Pepper-tree?

It is funny how a plant that started out as an ornamental and was even called “Florida Holly” at one time eventually was discovered in natural areas in the late 1950’s.  Once the Brazilian pepper-tree began to dominate parts of south Florida, many began to classify this tree an invasive exotic – a Category I Invasive considered both noxious and prohibited by the State of Florida.  Found in south Florida, as well as in protected sites in central and northern Florida, Brazilian pepper-trees colonize natural areas in stands of trees up to thirty-three feet tall.   Groups of trees form a twisted canopy of branches shading out everything below.  The bright red fruits produced are scattered by birds and mammals just about everywhere.  The seeds have a great germination rate, survival potential, and rapid growth.  This “King of Invasives” is ready to produce seeds in as little as three years! 

Other than finding and hand-picking seedlings that appear on your property, perhaps the best management suggestion is the use of certain herbicides to kill mature trees. Keep in mind - even if you are clearing Brazilian pepper on your property - to make sure that you get a permit from the County Community Development  Department before proceeding.  As Brazilian pepper is related to poison-ivy, you will want to wear protective gear to guard against, not only the potentially irritating sap and leaves, but also

the pesticide.  Using products formulated for use by homeowners such as glyphosate or triclopyr, and making sure to read the label before application,  carefully apply these to cut stumps.  Apply the herbicide to the freshly cut stump just inside the bark where the living layer of cambium tissue will rapidly take up the chemical and translocate it to the roots.  It is very important that this application be made within five minutes of the cut as the stump will begin to seal itself up after that time and prevent good herbicide transfer.  If  someone other than the  homeowner were to apply herbicides, they would need to be a Certified Applicator and have insurance.

While the cut-stump method is very popular, a basal bark application helped with the use of a penetrating oil, will actually go through the bark and kill the tree.  Foliar applications can also be used for seedlings.  While there is a seed-eating wasp present that can reduce some Brazilian pepper reproduction, and there are several other insect controls being looked at, there are no breakthrough biological controls available at this time.

The Brazilian pepper-tree is apparently here to stay.   The best you can do is push it back off your own property with focused efforts and techniques. For more information on all types of invasive plants found in our area,  please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer.  Don't forget to visit our other County Plant Clinics in the area.  Please check this link for a complete list of site locations, dates and times - http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.

Resources:

Gioeli, K. & Langeland,  K. (2015) Brazilian Pepper-tree Control.  The University of Florida Extension Service, IFAS.

Hall,  D. W., Vandiver, V. V.,  Sellers, B. A. & Langeland, K. A. (2012) Brazilian Pepper-tree, Schinus terebinthifolius. The University of Florida Extension Service, IFAS.

Cuda, J.P., Medal, J.C.,. Overholt, W.A , Vitorino,  M. D., &. Habeck, D.H (2013) Classical Biological Control of Brazilian Peppertree (Schinus terebinthifolia) in Florida. The University of Florida Extension Service, IFAS.

Cuda,  J. P., Wheeler,  G. S. & Habeck, D. H. (2014) Brazilian Peppertree Seed Chalcid, (unofficial common name) Megastigmus transvaalensis (Hymenoptera: Torymidae) .  The University of Florida Extension Service, IFAS.

2013  Florida Exotic Pest Plant Council - http://www.fleppc.org/list/FLEPPCPlantList2013-PRINTABLEwithlinkstoCAIPpages.pdf .  

Madagascar periwinkles rule

I know that I say it about a lot of flowers, but the Madagascar periwinkle is really something special.  This evergreen perennial is also sometimes called Vinca.  In addition to its original rose pink color, periwinkle flower colors range from white, red, purple, apricot and pink to bi-color blooms.  They don’t take a freeze well, but as far as summer bloomers that take the summer heat, these should be in your flower bed for 2015.

You can purchase ready-to-go plants or seeds to begin your periwinkle bed.  I started  some from a package of seeds last year and successfully had almost more than I could use.   Seeds take six to eight weeks to reach blooming size, so plan ahead.  A site in full sun with good drainage is required for periwinkles.  They do not like overly wet soil and root rots can develop – sometimes foliar diseases develop as well.  Three good months of blooming is a reasonable goal for this plant.

All is not always well in Periwinkle-Ville!  As mentioned earlier, although very heat tolerant, periwinkles do not like to be too wet. The arrival of heavy summer rains may promote and trigger a variety of fungal diseases that can take your periwinkles down.  Fortunately, if you have had  problems with mid-summer periwinkle failures,  there is a variety called ‘Cora’ which has bred-in foliage disease resistance.  ‘Cora’ periwinkles come in a good number of colors (and larger flowers) to satisfy any taste. 

While periwinkles can grow upwards to two to three feet at maturity and get a bit leggy, most will be around fourteen to sixteen inches tall.  Each plant develops into a mounding specimen suitable for edging, as groundcover, mass planting, cascading down a wall and even in a hanging basket.  Periwinkles flourish in poor soils, so don’t feel the need to add any organic matter which would tend to make the soil retain excess moisture.  Also, when planting, plant them high and not deeper as you might some seedlings.  Culturally, this will help reduce the chances of root tot issues. 

While periwinkles have their challenges, they are fully worthwhile and gardeners should plant more!  For more information on all types of flowers suitable for our area, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer.  Don't forget to visit our other County Plant Clinics in the area.  Please check this link for a complete list of site locations, dates and times - http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.

Resources:

Gilman, E. F. & Howe, T. (2011) Catharanthus roseus Periwinkle, Madagascar Periwinkle.  The University of Floruida Extension Service, IFAS. 

Christman, S. (2012) Catharanthus roseus.  Floridata.com, Tallahassee, FL.

Caldwell, D. (2008) A Rainey Season Periwinkle? The University of Floruida Extension Service, IFAS – Collier County.