White, Fluffy, Woolly Stuff on My Plants

White, Fluffy, Woolly Stuff on My Plants

Homeowner accounts of white fluffy woolly masses on woody ornamentals, oak trees and Muhly grass have been on the rise. The good news is they are native insects that need a nursery for their young and will cause little harm to the host plant.  The bad news is scientists know very little about the complete live cycle and role in the environment of these insects.

Within the cottony mass there are citrus flatid planthoppers, woolly oak aphids, or Muhly mealybugs. The adults have laid eggs or birthed their young on the leaves. The young nymphs have excreted large amounts of the woolly wax to protect them from predators and weather while they grow larger. Food from the plants is needed to grow, so these piercing-sucking insects are removing sugars from the host plant. But, typically it is not enough to significantly change the plant’s appearance, so most people are not alarmed until they notice “all the white stuff”.

Adult citrus flatid planthopper, Metcalfa pruinosa (Say). Credits: Photograph by: Lyle J. Buss, University of Florida

The only one that moves quickly are the citrus flatid planthoppers. When a person reaches for the flocked branch, something small moves and seems to jump at you. Most likely the jumping direction is away from you, but it still may be startling. They are planthoppers (Metcalfa pruinosa), an insect in the order Hemiptera.  As the name implies, they occur on citrus but can also be found on many woody ornamentals and other fruit trees.  The adult planthopper wing arrangement is tent-like, meaning that the forewings are held over the insect abdomen in a tent configuration.

Stegophylla brevirostris Quednau colony on oak. Photograph by Susan E. Halbert

Woolly oak aphids are conspicuous pests on oak (Quercus spp.), because they are covered with large amounts of flocculent wax. Two genera of woolly oak aphids occur in Florida. One species, Stegophylla brevirostris Quednau, is common, and the other, Diphyllaphis microtrema Quednau, is rare. Florida woolly oak aphids are recognized easily by the large quantities of woolly wax that they secrete. Beneath the wax, aphid bodies are pale. Young nymphs are typically pale green, and they tend to be more mobile than adults. The majority of reports of woolly oak aphids indicate a preference for live oak (Quercus virginiana Mill.) as the host. These aphids are live-bearing females. It is not known how these aphids disperse, but possibly they are picked up and carried by birds and larger flying insects because of the sticky wax that surrounds the bodies of the aphids.

Muhly grass infested with mealybug. Photo: Beth Bolles

Muhly grass (Muhlenbergia capillaris) is a generally pest free plant in its native habitat, however, the native mealybug, Stemmatomerinx acircula, has made an appearance on plants in various landscapes. Insects feed on the leaves and are grey with white wax that may have some filaments. You may also see long ovisacs on the leaves which contain eggs and crawlers. With close inspection, you will notice they have legs and can move about.

So “what do you do?’  If the plant doesn’t appear to be suffering, let nature take its course. “This to will pass.” If someone demands perfection, use insecticidal soap to reduce the population.  The soft-bodied creatures will dry up before they can become adults. To read more about these odd creatures of nature go to: https://entnemdept.ufl.edu/creatures/

Fall color in the Panhandle

Fall color in the Panhandle

Perpetual Question

Do any of the leaves change color down here in the fall?  The most common answer is that there is none here in the land of evergreens.  The prevalence of oaks (Quercus spp.) and pines (Pinus spp.) see to that.  There is hope. Deciduous trees put on a show as the need for photosynthesis reduces. Chlorophyll production stops replaced with anthocyanins and carotenoids.  As they take over, the beautiful display we all love begins. Several tree species thrive in the panhandle and have great autumn foliage. Once you know which, you’ll see a color pallet that would make DaVinci himself drool.   

Tree for all seasons

Sweet gum (Liquidambar styraciflua) is a larger tree growing upwards of 75 feet tall with a 50 foot spread.  The canopy has an early conical shape which evolves into an oval as the tree ages. This tree is excellent for local parks and to provide shade in your front yard.  Red tinged flowers produced in spring combined with multi-shaded leaves provide interest throughout the year.  However, autumn this tree comes into its own. As the days shorten and cool these leaves begin their journey to the ground by taking on shades of yellow, orange, red, or burgundy.   

IFAS photograph Heather Kalaman

Panhandle Delight

A unique tree growing primarily in the Panhandle, the Florida maple (Acer floridanum) puts on an excellent autumn show.  At that time of year, the leaves will change to a muted yellow or orange color.  Reaching 60 feet high and 30 wide this oval canopied tree is ideal for shade or along streets.  Fall is the only time you will see color changes from this tree, but in summer you’ll be treated to that classic maple leaf shape.

IFAS Photograph

An Oddity of a Tree

The bald cypress (Taxodium distichum) is a tree rife with oddity.  Growing at times as high as 80 feet with a roughly 35 foot spread these trees excel in your lawn. Be wary as when grown in wet environments they develop “knees” thought to help aerate roots in standing water. Ball shaped cones are the primary reproductive organs of this tree. For the purposes of this article, we’ll focus on the color changing needles.  When winter is nigh, they change from pale green to an eye catching yellow or rusty copper. One of the few deciduous conifers, the needles will fall off revealing peeled bark for winter interest.

IFAS Photograph Kathy Warner

To Sum it Up

These are but a few of the trees in north Florida known to change color in the autumn. The list is not overly exhaustive, but there are several in this category.  For more information on landscape trees, see this Ask IFAS document, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.

Threadleaf Sundews: Local Carnivorous Plants

Threadleaf Sundews: Local Carnivorous Plants

A threadleaf sundew in bloom, with its series of buds trailing down. Photo credit: Carrie Stevenson, UF IFAS Extension

The mucky, sunny spaces here in northwest Florida are inevitably full of beauty and surprises. Due to the sopping wet, acidic, and nutrient poor soil, plants in these areas must make some unusual adaptations. Wetland bogs are home to several interesting and carnivorous species, like pitcher plants and sundews. Most sundew species I come across are the tiny, pinwheel shaped dwarf sundews (Drosera brevifolia), which lie prone to the ground.

At a recent visit to the Roy Hyatt Environmental Center, I noticed a showy purple flower that at first I assumed was a meadow beauty.

Threadleaf sundew leaves glisten in the sunlight adjacent to a crop of purple flowers growing from separate stems. Photo credit: Hugh and Carol Nourse

Lavender, four-petaled meadow beauty flowers are common in wet areas. However, this plant was a bit different. First, it had five petals; but even more unusual was that something akin to a green caterpillar was hanging from every flower bloom. Intrigued, I bent closer and saw that the green segments were not a dangling invertebrate, but a series of fuzzy green flower buds. The bud closest to the purple flower was a deep violet and close to flowering.

Fields of curled fiddlehead leaves of the threadleaf sundew are a whimsical sight in wetland bogs. Photo credit: North Carolina State Extension Service (NCSES)

In all my years of exploring and leading people around pitcher plant prairies, I’ve encountered Tracy’s sundew/threadleaf sundew (Drosera tracyi)—a type of sundew with an upright, sap-covered stem—but never one in bloom.

Up-close view of a Drosera tracyi leaf. Photo credit: NC State Extension

Typically, you’ll only come across the slender, threadlike ( a structure known as “filiform”) fiddlehead leaves. These leaves look more like stems, and are bright green and covered in dewy, sticky, deadly-to-insects droplets. Insects are attracted to the shimmering drops of mucus, triggering a hormone in the plant that causes the leaf and its glands to fold over the prey. Once stuck, the insects suffocate and are digested by enzymes in the leaf glands.

The purple flowers appear in May or June, atop a single leafless stem that appears unattached to the threadleaf sundew leaves. According to the Georgia Biodiversity Portal, this series of flowers will “open one by one, from the bottom of a coiled inflorescence up, with unopened buds at the top. Flowers begin to open about 9:00 am and close about five hours later; some flowers persist for two days.” Threadleaf sundews can self-pollinate but are also attractive to bees.

A Favorite Native Shrub

A Favorite Native Shrub

Strawberry bush with new spring growth. Photo by Beth Bolles, UF IFAS Extension Escambia County.

When I was first planting a landscape in 2001, I wanted to include some interesting native plants to provide a natural look for the back edges of the property.  I was able to find a few less commonly sold natives from a small local nursery including a Bigleaf magnolia, Vaccinium, Sourwood, Cinnamon fern, and Strawberry bush.

Twenty years later, I am still enjoying these natives in my landscape and they are doing well despite my sandy, well drained, nutrient poor conditions.  One of my favorites of this group is the Strawberry bush, Euonymous americana.

Strawberry bush is a deciduous shrub that grows about five feet tall. It has multiple stems with new stems forming each season.  Since my yard is so dry, my clump is by no means out of bounds after 20 years of growth.  Small pale green flowers grow from the nodes in spring.  For most of the year, you forget about this plant until one day in the fall, you notice brilliant red fruits that split open to show orange seeds.  Another common name is Hearts-a-bustin’.

Fall color with Strawberry bush. Photo by Beth Bolles, UF IFAS Extension Escambia County.

Despite one of its common names, Strawberry bush is not grown as an edible for people but serves as a wildlife food source.  Deer may enjoy leaves and twigs and many birds and small mammals will eat the seeds.

If you find a local nursery that is growing a few, consider adding Strawberry bush to a shaded spot in your landscape.

Dwarf Walter’s Viburnum:  A Great Native Shrub for Deep South Landscapes

Dwarf Walter’s Viburnum:  A Great Native Shrub for Deep South Landscapes

Lost in the sea of more popular and showy spring-flowering landscape shrubs like azalea, spirea, and the like, is an underused, exceedingly tough, and currently flowering Florida native shrub that is deserving of a spot in your landscape, Walter’s Viburnum (Viburnum obovatum).

Species Walter’s Viburnum (Viburnum obovatum). Photo Credit: UF/IFAS.

Walter’s Viburnum, named for English-born botanist turned South Carolina farmer Thomas Walter, who first described the species in the late 1700’s, is a spring-flowering mostly evergreen shrub/small tree native to the Southeastern United States.  In its native environment around hammocks, swamp edges, and near-river forests beneath the understory of canopy trees, Walter’s specimens often grow to around 15’ in height, live for more than 50 years, and spread slowly into loose thickets from their extensive underground root system.  After covering themselves in clusters of small, showy, pollinator-attracting white flowers in spring, Walter’s produces small reddish-black fruit that are magnets for birds and other small wildlife in summer.

Though this tough, low-maintenance nature and gorgeous pure white March flower display should have seemingly enabled Walter’s to be a standout in the landscape, Walter’s Viburnum languished in popularity for many years as it didn’t fit into most landscapes in its wild form.  Not too many folks in modern landscape situations are looking for a thicket forming, unkempt-looking tree!  However, with increased breeding efforts aimed at selecting superior dwarf varieties and the rise in interest in using low-maintenance native plants, Walter’s has rapidly gained market share on traditional flowering shrubs in nurseries and yards in across Florida.

These newer dwarf varieties of Walter’s, including standouts like ‘Mrs. Schiller’s Delight’ and my personal favorite ‘Whorled Class’, only grow 3-4’ in height and make an excellent replacement for more commonly planted small foundation shrubs.  Why plant a disease-prone Boxwood when you can have a disease-resistant native dwarf Walter’s Viburnum?  Why allow your landscape to be saddled with drab Dwarf Yaupon Holly when you could get the same basic effect AND an awesome flower show by planting a dwarf Walter’s?  Tired of having to constantly prune those Loropetalum or Azaleas to keep them from hiding the house?  I think you know the answer by now; plant a slow-growing dwarf Walter’s!

‘Whorled Class’ dwarf Walter’s Viburnum in a Calhoun County, FL landscape. Photo Credit: Daniel Leonard, University of Florida/IFAS Extension – Calhoun County.

Both the “wild-type” Walter’s Viburnum and the newer dwarf cultivars are about as low maintenance landscape shrubs as one could want.  Though Walter’s normally occurs in shaded understory situations with moist, acidic soils in the wild, it is very adaptable to all manner of landscape situations.  The species takes full sun extremely well but will also thrive with shade.  It will tolerate very moist soil but, once established, is drought tolerant.  I fertilize my Walter’s plants each spring with a general purpose, balanced garden fertilizer to boost growth, but there are many plantings of the species that get by without supplemental fertilizer.  Finally, due to the dwarfing nature of the previously mentioned Walter’s cultivars, constant shearing won’t be necessary to maintain a pleasing shape, but they do respond well to pruning when a haircut is needed!

If you’ve been looking to include something a little bit different from the standard spring flowering fare in your landscape but also require your plants to be tough adaptable, try Walter’s Viburnum, especially the cultivars ‘Whorled Class’ or ‘Mrs. Schiller’s Delight’.  They’ll be attractive, low-maintenance additions to nearly any Panhandle landscape for years to come!  For more information about Walter’s Viburnum or any other horticultural or agricultural topic, contact your local UF/IFAS County Extension office. Happy gardening!


Native Azaleas in Bloom

Native Azaleas in Bloom

piedmont azalea

Piedmont azalea (Rhododendron canescens) flowers. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

Native azaleas are stunning this time of year.  These deciduous shrubs (and sometimes small trees) often go unnoticed until they bloom in the spring.  Three species native to Florida are the piedmont azalea (Rhododendron canescens), the Florida flame azalea (Rhododendron austrinum), and the swamp azalea (Rhododendron viscosum).  Piedmont azaleas have whitish to pinkish blooms, Florida flame azaleas have yellow to orange blooms, and the white blooms.  All three species have a wonderful honeysuckle-like, sweet fragrance.  All three serve as outstanding focal points in the landscape.

Native azaleas and other deciduous azaleas have varying site preferences.  Like other azaleas, piedmont and Florida flame azaleas prefer moist, well-drained, acidic soils.  However, as the name would suggest, the swamp azalea tolerates wetter locations.  All three species prefer partial shade (morning sun and afternoon shade are best) locations and can grow up to 15 feet tall.

Rhododendron x 'Aromi Sunny-Side-Up' in bloom.

Rhododendron x ‘Aromi Sunny-Side-Up’ in bloom. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

In addition to these beautiful native azaleas, a number of deciduous hybrids have been developed.  Aromi hybrids have been bred to tolerate heat and humidity.  These azaleas were developed from four native species ()from Gene Aromi in Mobile, AL.  He developed more than 100 cultivated varieties (also referred to as cultivars).  Popular cultivars in the market include ‘Centerpiece’, ‘Aromi Sunrise’, and ‘Aromi Sunny-Side-Up’.

Deciduous azaleas do not require a lot of fertilizer.  A controlled release or slow release, acid forming (specifically formulated for azaleas or blueberries) fertilizer is recommended.  A fertilizer nutrient ratio of or close to 2-1-1 (N-P-K) should be selected.  Plants should be fertilized in spring or early summer, never in the fall or winter.

More information on azales, native and nonnative, can be found on the UF/IFAS Gardening Solutions website.