Green Roofs

Green Roofs

The Florida state wildflower, coreopsis, in bloom atop the Escambia County green roof. Photo credit: UF IFAS Extension

Most of us don’t think much about our roofs until there is a problem—a storm blows off shingles, causing a leak, necessitating a giant blue tarp to hold off the rain until we can get a contractor to replace the roof. But “a roof over your head” is one of those basic needs, perhaps only slightly less necessary for safety and survival than food and water.

Stormwater engineers and landscape architects have been thinking a lot about rooftops. Along with hard surfaces like roads and parking lots, roof area in a community is one of the biggest contributors of stormwater runoff. Those impervious surfaces don’t absorb any rainwater, contributing both to the volume and pollution potential of runoff from any given storm.

The skyline of downtown Kalamazoo, Michigan, as viewed from their City Hall green roof. Photo credit: Carrie Stevenson, UF IFAS Extension

While only applicable in specific situations, green roofs can provide a practical and beautiful solution to this problem. Escambia County has been home to the state’s largest green roof since 2009, housed atop the county’s Central Office Complex (COC). At over 33,000 square feet, it can absorb nearly 20,000 gallons of water during a rain, reducing flooding in a flood-prone area and allowing rain to soak into soil instead of becoming runoff. The COC roof was part of the building’s design from the beginning, but many commercial and government buildings have added green roofs as part of a retrofit. The rule of thumb is that if the building is sturdy enough to support an additional story, it can handle the weight of a green roof—including soil, vegetation, and water storage.

Last month, I visited the green roof atop Kalamazoo, Michigan’s City Hall. The imposing art deco building was constructed in the 1930’s, but the green roof on the building’s perimeter was added in 2011. Green roofs add tremendous environmental benefits but can be cost prohibitive, so many communities find grant funding (like the state of Florida’s Nonpoint Source Management grants) to help cover the expense. The Escambia County and Kalamazoo green roofs were both funded by grants. Besides the runoff reductions, a green roof can provide significant energy savings. Vegetation buffers a building from the incredibly hot summer rooftop temperatures, reducing the use of air conditioning and stabilizing indoor temperatures. This is the case for the Escambia County roof, in which an audit showed a 33% reduction in energy needs when compared to a conventionally designed building.

Green roofs can be built on flat-topped home roofs, and many European countries use them regularly. Plant selection for green roofs varies widely based on climate. Our local roof is mostly planted with beach dune species, while cooler, less humid regions make ample use of succulents like sedums. Low growing grasses and native wildflowers are great choices everywhere, providing color with limited maintenance.

Florida’s State Wildflower is Great for Pollinators: Coreopsis

Florida’s State Wildflower is Great for Pollinators: Coreopsis

Coreopsis flowers. Photo courtesy UF/IFAS.

A beautiful wildflower that lines the roads and open areas is one of my favorite native pollinating plants. Coreopsis also commonly known as Tickseed was designated our Florida State Wildflower in 1991. It can be found throughout Florida and all 17 species occur in North Florida. Varieties such as Leavenworth’s Swamp (C.nudata), Florida (C. floridana) and Coastalplain (C. gladiata) are found in moist areas and other varieties like Lanceleaf Tickseed (C. lanceolata) and Goldenmane Tickseed (C. basalis) are commonly found in the drier areas of the landscape.

All the varieties of Tickseeds have daisy-like flowers with yellow petals except for the Swamp Tickseed which is more pinkish purple in color. The flower gets its common name by the appearance of the small ovalish seed that has two short spines at one end and looks like a ‘tick’. The most common coreopsis is Coreopsis leavenworthii. This plant can be found in moist pinelands and disturbed sites. You can spot the blooms of bright yellow ray petals with brownish central disk flowers from late spring through late fall. This coreopsis can reach 3 feet in height. It grows like a weed and can quickly establish itself on bare soil. Coreopsis is essentially an annual with our colder winters but produces many seeds that will multiply as long as the plant receives adequate sun and moisture. A special species of coreopsis found only here in the Panhandle is the Chipola coreopsis (C. integrifolia). It is less common and only found along the Chipola River. This 18-24” plant has deep green oval-shaped leaves and deep yellow flowers seen blooming in the Fall, maybe a great time to go kayaking or hiking along the river! The Chipola coreopsis prefers moist soils and some protection from the sun. This variety is so rare that it has been listed endangered by the Florida Department of Agriculture.

Native Lanceleaf Coreopsis. UF/IFAS Photo: Thomas Wright.

Coreopsis is pollinated mostly by small bees and not visited as much by butterflies and other pollinators. They are a great plant to use for a show of color! You can get seeds from your local garden center or from the Florida Wildflower Growers Cooperative (https://floridawildflowers.com). This Florida-Friendly plant is drought tolerant and can be sown anytime from October to January.

Sources:
https://www.flawildflowers.org/wp-content/resources/pdfs/Publications/AboutCoreopsis.pdf 
https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/coreopsis.html

Coastal Plain Honeycombhead and the Gulf Coast Solitary Bee

Coastal Plain Honeycombhead and the Gulf Coast Solitary Bee

Coastal plain honeycombhead blooms through the summer and early fall on local beaches. Photo credit, Bob Pitts, National Park Service

Over my years of leading people on interpretive trail hikes, I have learned it is particularly important to know the names of the plants that are in bloom. These flowers are eye-catching, and inevitably someone will ask what they are. In fact, one of my favorite wildflower identification books is categorized not by taxonomy, but by bloom color—with a rainbow of tabs down the edge of the book for easy identification.

Wildflower identification can be tough, but color-coded guidebooks are really helpful! Photo credit: Carrie Stevenson, UF IFAS Extension

In our coastal dunes right now, several plants are showing off vibrant yellow blooms. Seaside goldenrod, coreopsis, and other asters are common. Rarer, and the subject of today’s post, is the Coastal Plain Honeycombhead (Balduina angustifolia). It has bright yellow flowers, but often gets more notice due to its unusual appearance when not in bloom. The basal leaves are bright green and similar in shape and arrangement to a pine cone or bottlebrush (albeit a tiny one), sticking straight up in the sand. The plants are typically found on the more protected back side of primary dunes or further into secondary dunes, a little more inland from the Gulf.

When not in bloom, the plant resembles a green pinecone planted in the sand. Photo credit: Carrie Stevenson, UF IFAS Extension

The plant plays a special role in beach ecology, as a host plant for Gulf fritillary butterflies and the Gulf Coast solitary bee (Hesperapis oraria). The bee is a ground-dwelling pollinator insect that forages only in the barrier islands of Mississippi, Alabama, and Florida. The species is currently the subject of a University of Florida study, as the endemic bee’s sole source of nectar and pollen is the honeycombhead flower. As of publication date, no bee nests have been discovered. Researchers are interested in learning more about the insect’s life cycle and nesting behaviors to better understand and protect its use of local habitats. Based on closely related species, it is believed the Gulf Coast solitary bee builds a multi-chambered nest under the soft sands of the dunes.

Adult female Hesperapis oraria foraging on coastal plain honeycombhead (Balduina angustifolia). Photograph by John Bente, Florida Department of Environmental Protection, Florida Park Service.

While the honeycombhead plant is found in peninsular Florida and coastal Georgia, the bee has been identified only in a 100 km² area between Horn Island, MS, and St. Andrews Bay, FL. Luckily for the bee, large swaths of this land are preserved as part of Gulf Islands National Seashore and several state parks. Nonetheless, these coastal dune habitats are threatened by hurricanes, sea level rise, and development (outside the park boundaries).  Due to its rarity and limited habitat, a petition has been submitted to the Fish and Wildlife Service for protection under the Endangered Species Act.

False Foxglove:  A Unique Fall Wildflower

False Foxglove: A Unique Fall Wildflower

False Foxglove in a Calhoun County natural area. Photo courtesy of Daniel Leonard.

Fall is the absolute best season for wildflower watching in the Panhandle!  When mid-September rolls around and the long days of summer finally shorten, giving way to drier air and cooler nights, northwest Florida experiences a wildflower color explosion.  From the brilliant yellow of Swamp Sunflower and Goldenrod, to the soothing blue of Mistflower, and the white-on-gold of Spanish Needles, there is no shortage of sights to see from now until frost.  But, in my opinion, the star of the fall show is the currently flowering False Foxglove (Agalinus spp.).

Named for the appearance of their brilliant pink flowers, which bear a resemblance to the northern favorite Foxglove (Digitalis spp.), “False Foxglove” is actually the common name of several closely related species of parasitic plants in the genus Agalinus that are difficult to distinguish by all but the keenest of botanists.  Regardless of which species you may see, False Foxglove is an unusual and important Florida native plant.  Emerging from seed each spring in the Panhandle, plants grow quickly through the summer to a mature height of 3-5’.  During this time, False Foxglove is about as inconspicuous a plant as grows.  Consisting of a wispy thin woody stem with very small, narrow leaves, plants remain hidden in the flatwoods and sand hill landscapes that they inhabit.  However, when those aforementioned shorter September days arrive, False Foxglove explodes into flower sporting sprays of dozens of light purple to pink tubular-shaped flowers that remain until frost ends the season.

False Foxglove flowering in a Calhoun County natural area. Photo courtesy of Daniel Leonard.

In addition to being unmatched in flower, False Foxglove also plays several important ecological roles in Florida’s natural areas.  First, False Foxglove’s relatively large, tubular-shaped flowers are the preferred nectar sources for the larger-sized native solitary and bumble bees present in the Panhandle, though all manner of generalist bees and butterflies will also visit for a quick sip.  Second, False Foxglove is the primary host plant for the unique Common Buckeye butterfly.  One of the most easily recognizable butterflies due to the large “eye” spots on their wings, Common Buckeye larvae (caterpillars), feed on False Foxglove foliage during the summer before emerging as adults and adding to the fall spectacle.  Finally, False Foxglove is an important indicator of a healthy native ecosystem.  As a parasitic plant, False Foxglove obtains nutrients and energy by photosynthesis AND by using specialized roots to tap into the roots of nearby suitable hosts (native grasses and other plants).  As both False Foxglove and its parasitic host plants prefer to grow in the sunny, fire-exposed pine flatwoods and sand ridges that characterized pre-settlement Florida, you can be fairly confident that if you see a natural area with an abundance of False Foxglove in flower, that spot is in good ecological shape!

The Florida Panhandle is nearly unmatched in its fall wildflower diversity and False Foxglove plays a critical part in the show.  From its stunning flowers to its important ecological roles, one would be hard-pressed to find a more unique native wildflower!  For more information about False Foxglove and other Florida native wildflowers, contact your local UF/IFAS County Extension office.

 

Rainlily: A Rewarding Bulb for Panhandle Gardeners

Rainlily: A Rewarding Bulb for Panhandle Gardeners

Bulbs are my favorite class of ornamental plants.  They generally are low maintenance, come back reliably year after year, and sport the showiest flowers around.  While many bulbs like Daylily, Crinum and Amaryllis are very common in Panhandle landscapes, there is a lesser-known genus of bulbs that is well worth your time and garden space, the Rainlily (Zephyranthes spp.).

Rainlily, aptly named for its habit of blooming shortly after summer rainfall events and a member of the Amaryllis family of bulbs, is a perfect little plant for Panhandle yards for several reasons.  The plant’s genus name, Zephyranthes – which translates to English as “flowers of the western winds”, hints at the beauty awaiting those who plant this lovely little bulb.  From late spring until the frosts of fall, Rainlily rewards gardeners with flushes of trumpet-shaped flowers in shades of white, pink, and yellow, with some hybrids offering even more exotic colors.  While these individual flowers typically only persist for a day or two, they are produced in “flushes” that last several days, extending the show.  Though Rainlily flowers are the main event for the genus, beneath the blooms, plants also offer attractive, grass-like, evergreen foliage.  These aesthetic attributes lend themselves to Rainlily being used in a variety of ways in landscapes, from massing for summer color ala Daylilies, to use around the edges of beds as a showy border like Liriope or other “border” type grassy plants.

Unknown Rainlily species blooming in a raised bed. Photo courtesy of Daniel Leonard.

Continuing along the list of Rainlily attributes, the genus doesn’t require much in the way of care from gardeners either.  Most species of Rainlily, including the Florida native Z. atamasca, have no serious pests and are right at home in full sun to part shade.  Once established, plants are exceedingly low-maintenance and won’t require any supplemental irrigation or fertilizer!  Some Rainlily species like Z. candida even make excellent water or ditch garden plants, preferring to have their feet wet most of the year – putting them right at home in the Panhandle this year.  And finally, all Zephyranthes spp. do very well in containers and raised beds also, adding versatility to their use in your landscape!

The one drawback of Rainlily is that they can be somewhat difficult to find for sale.  As these bulbs are an uncommon sight in most garden centers, to source a specific Zephyranthes species or cultivar, one is probably going to need to purchase from a specialty internet or mail-order nursery.  As with other passalong-type bulbs though, the absolute best and most rewarding way to obtain Rainlily is to get a dormant season bulb division from a friend or fellow gardener who grows them.  There are many excellent unnamed or forgotten Zephyranthes cultivars and seedlings flourishing in gardens across the South, waiting to be passed around to the next generation of folks who will appreciate them!

Even if you must go to some lengths to get a Rainlily in your garden, I highly recommend doing so!  You’ll be rewarded with years of low-maintenance summer color after the dreariest of rainy days and will be able to pass these “flowers of the western wind” on to the next gardening generation.  For more information on growing, sourcing, or propagating Rainlilies, check out this EDIS publication by Dr. Gary Knox of the UF/IFAS North Florida Research and Education Center (NFREC) or contact your local UF/IFAS Extension office!  Happy Gardening!

 

 

 

Landscape  Q & A

Landscape Q & A

On August 12, 2021, our panel answered questions on a wide variety of landscape topics. Maybe you are asking the same questions, so read on!

Ideas on choosing plants

What are some perennials that can be planted this late in the summer but will still bloom through the cooler months into fall?

Duranta erecta ‘Sapphire Showers’ or ‘Gold Mound’, firespike, Senna bicapsularis, shrimp plant, lion’s ear

Where can native plants be obtained?

Dune sunflower, Helianthus debilis. Photo credit: Mary Salinas UF/IFAS Extension.

Gardening Solutions: Florida Native Plants  – see link to FANN: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/native-plants.html

What are some evergreen groundcover options for our area?

Mondo grass, Japanese plum yew, shore juniper, ajuga, ferns such as autumn fern.

What are some ideas for partial morning sun butterfly attracting tall flowers to plant now?

Milkweed, salt and pepper plant, swamp sunflower, dune sunflower, ironweed, porterweed, and salt bush.

I’m interested in moving away from a monoculture lawn. What are some suggestions for alternatives?

Perennial peanut, powderpuff mimosa, and frogfruit.

We are new to Florida and have questions about everything in our landscape.

Florida-Friendly-Landscaping TM Program and FFL Web Apps: https://ffl.ifas.ufl.edu/

https://ffl.ifas.ufl.edu/resources/apps/

UF IFAS Gardening Solutions: https://gardeningsolutions.ifas.ufl.edu/

What are some of the top trends in landscaping today?

Houseplants, edible gardens, native plants, food forests, attracting wildlife, container gardening, and zoysiagrass lawns

Edibles

Artwork broccoli is a variety that produces small heads. Photo credit: Mary Salinas UF/IFAS Extension.

What vegetables are suitable for fall/winter gardening?

Cool Season Vegetables: https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/cool-season-vegetables.html

North Florida Gardening Calendar: https://edis.ifas.ufl.edu/publication/EP451%20%20%20

Florida Vegetable Gardening Guide: https://edis.ifas.ufl.edu/publication/vh021

How can I add herbs to my landscape?

Herbs in the Florida Garden: https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/herbs.html

My figs are green and hard. When do they ripen?

Why Won’t My Figs Ripen: https://www.lsuagcenter.com/profiles/rbogren/articles/page1597952870939

What is best soil for raised bed vegetable gardens?

Gardening in Raised Beds: https://edis.ifas.ufl.edu/publication/EP472

And there are always questions about weeds

How can I eradicate cogongrass?

Chamber bitter is a troublesome warm season weed in our region. Photo credit: Brantlee Spakes Richter, University of Florida, Bugwood.org

Cogongrass: https://edis.ifas.ufl.edu/publication/WG202

Is it okay to use cardboard for weed control?

The Cardboard Controversy: https://gardenprofessors.com/the-cardboard-controversy/

What is the best way to control weeds in grass and landscape beds?

Weed Management Guide for Florida Lawns: https://edis.ifas.ufl.edu/publication/EP141

Improving Weed Control in Landscape Planting Beds: https://edis.ifas.ufl.edu/pdf/EP/EP52300.pdf

Landscape practices

Can ground water be brackish and stunt plants?

Reclaimed Water Use in the Landscape: https://edis.ifas.ufl.edu/publication/ss545

How can I prevent erosion from rainwater runoff? 

Stormwater Runoff Control – NRCS: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/water/?cid=nrcs144p2_027171

Rain Gardens: https://gardeningsolutions.ifas.ufl.edu/design/types-of-gardens/rain-gardens.html

And https://gardeningsolutions.ifas.ufl.edu/pdf/articles/rain-garden-manual-hillsborough.pdf

What is the best time of the year to propagate flowering trees in zone 8B?

Landscape Plant Propagation Information Page – UF/IFAS Env. Hort: https://hort.ifas.ufl.edu/database/lppi/

Which type of mulch works best on slopes greater than 3 percent?

Landscape Mulches: How Quickly do they Settle?: https://edis.ifas.ufl.edu/publication/FR052

When should bulbs be fertilized?

Bulbs and More – UI Extension: https://web.extension.illinois.edu/bulbs/planting.cfm

Should I cut the spent blooms of agapanthus?

Agapanthus, extending the bloom time: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/agapanthus.html

http://blogs.ifas.ufl.edu/wakullaco/2020/10/07/extending-bloom-time/

Plant questions

Monarch caterpillar munching on our native sandhill milkweed, Asclepias humistrata. Photo credit: Mary Salinas, UF IFAS Extension.

I planted native milkweed and have many monarch caterpillars. Should I protect them or leave them in nature?

It’s best to leave them in place. Featured Creatures: Monarch Butterfly: https://edis.ifas.ufl.edu/pdf/IN/IN780/IN780-Dxyup8sjiv.pdf

How does Vinca (periwinkle) do in direct sun? Will it make it through one of our panhandle summers? Can I plant in late August?

Periwinkles  and  No more fail with Cora series: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/periwinkles.html#:~:text=Plant%20your%20periwinkles%20where%20they,rot%20if%20irrigated%20too%20frequently.

Insect and disease pests

What to do if you get termites in your raised bed?

The Facts About Termites and Mulch: https://edis.ifas.ufl.edu/publication/IN651

How to combat fungus?

Guidelines for ID and Management of Plant Disease Problems: https://edis.ifas.ufl.edu/publication/mg442

Are there preventative measures to prevent diseases when the humidity is very high and it is hot?

Fungi in Your Landscape by Maxine Hunter: http://blogs.ifas.ufl.edu/marionco/2020/01/16/fungi-in-your-landscape/

 

If you missed an episode, check out our playlist on YouTube https://www.youtube.com/watch?v=bp0HfdEkIQw&list=PLhgoAzWbtRXImdFE8Jdt0jsAOd-XldNCd