Yuccas – one spiny, one soft

Is the  yucca plant new to you?   This arid  plant may look interesting enough to add to your landscape plant palette choices. Yuccas are plants that have stiff, dagger-like leaves and stunning spikes of white flowers.  Drought-tolerant and hardy, yuccas are Florida-Friendly Landscaping™ plants worthy of your attention.

First, a word of caution - with common names such as Spanish Bayonet, some yuccas are known for their dangerously sharp needle-like tips.  Fortunately, these sharp tips can be rendered harmless by clipping them off with pruners.  There is also a spineless yucca which has needle-less leaves.

A Florida native yucca, the Spanish Bayonet or Yucca aloifolia, is a tall plant up to fifteen feet in height which may even form multi-stemmed clumps.  The dark green leaves of this yucca must be de-needled with pruners for safety purposes.  If you want these plants fully armed with their needles, this yucca should be placed away from areas where people may travel. Otherwise, they can used as spiny security plants strategically placed near sites where you do not want intruders.  Yucca aloifolia is known to occasionally fall over and start new plants, so give them plenty of space for expansion.   A very drought-tolerant plant, the leaf margins of this yucca are rough to the touch.  Although the Spanish Bayonet prefers full sun to part shade, they will even thrive in almost full shade conditions.  One colorful cultivar to look for is called ‘Tricolor’ which has green and white leaves. 

For those gardeners that want a naturally “de-clawed” yucca, try the Spineless Yucca, a.k.a. Soft-Tip Yucca or Yucca elephantipes.  Brought to Florida in 1956, and much taller than the other yuccas, the Spineless Yucca grows up to thirty-feet tall and fifteen feet wide.  This non-native yucca is a very fast grower in comparison with the other yuccas and has a large single trunk with impressive four-foot-long leaves.  A multi-trunked tree may develop over time from sprouts at the base.  Once they reach eight to ten feet tall, Spineless Yuccas are able to produce a spectacular three-foot-tall bloom.   This yucca can also be kept as a houseplant.  In the landscape, the Spineless Yucca must have excellent drainage.

Yuccas, both spiny and spineless, can make an interesting accent to your landscape, so make it a point to add one to your yard!  For more information on all types of different ornamental plant materials 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. & Watson, D. G. (2011) Yucca elephantipes : Spineless Yucca.  The University of Florida Extension Service, IFAS.

Gilman, E. F. & Watson, D. G. (2011) Yucca elephantipes 'Variegata': Variegated Spineless Yucca. The University of Florida Extension Service, IFAS.

Gilman, E. F. (2011) Yucca aloifolia.  The University of Florida Extension Service, IFAS.

Knox, G. W. (2013) Agave and Yucca: Tough Plants for Tough Times.  The University of Florida Extension Service, IFAS.

Brown, S. H. (2012) Yucca aloifolia. The University of Florida Extension Service, IFAS – Lee County.

Christman, S. (2004) Yucca aloifolia. Floridata.com, Tallahasshee, FL. 

May 2015 Florida-Friendly Landscaping Series

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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