Heating up with Hardy Hibiscus

Each time I travel to central and south Florida and observe the wonderfully flamboyant tropical flora, I am reminded of the unique and frustrating climatic characteristics of Northwest Florida.  Our weather is tropical enough through the summer to sustain virtually everything our friends to the south grow, but winters north of the Big Bend are just cold enough to prevent long-term success with most tropical species.  However, the genus that is maybe most synonymous with tropical color, the Hibiscus (it even has its own texting emoji!), contains several species that are hardy through our winters.  The best landscape plant of these hardy Hibiscus species is creatively (sarcasm) called Hardy Hibiscus or Giant Rose Mallow (Hibiscus moscheutos) and is an absolute star in the Panhandle, bringing the beauty of the tropics to your yard!

Hibiscus ‘Starry Starry Night’ – Photo courtesy Daniel Leonard

Rose Mallow is a native perennial species that occurs in sunny wetlands across the eastern U.S.  This species can grow 7-8’ in height in its natural, unimproved state and possesses the largest flowers of any hardy perennial, some varieties easily eclipse 12” in diameter.  Rose Mallows bloom through the heat of our long summers and return reliably each winter unfazed by frost.  The flowers also happen to be a favorite of butterflies and hummingbirds and bring beneficial wildlife to the landscape.  These characteristics and the trend towards the use of pollinator friendly, low-maintenance native perennials in landscapes quickly made Rose Mallow a jewel for plant breeders and now virtually all major horticultural brands have a line of Hardy Hibiscus available at garden centers, in varying sizes, flower color and leaf color/form.  Recent breeding efforts have focused on introducing plants with enormous, richly colored flowers held on compact plants with attractive foliage.  The results have yielded two series and three individual cultivars that I consider superior selections and are more than worthy of inclusion in your garden:

  • Summerific® Series by Proven Winners. This series is comprised of four robust (up to 5’ in height) cultivars, ‘Cherry Cheesecake’ (bicolor magenta and white flowers), ‘Berry Awesome’ (purplish lavender flowers), ‘Cranberry Crush’ (a red you really have to see to believe), and ‘Perfect Storm’ (notable for its deep purple foliage).
  • Luna Series by Monrovia. This series is notable for its ultra-compact (3’ in height or less) size and characteristically large flowers.  It is also composed of four cultivars, ‘Luna Red’ (deep red), ‘Luna Blush’ (white, fading to pink near flower margins), ‘Luna Pink Swirl’ (pictured and my favorite, bicolor swirly flowers), and ‘Luna White’ (white with a red center).

    Hibiscus ‘Luna Pink Swirl’ – Photo courtesy Daniel Leonard

  • ‘Starry Starry Night’ by Walter’s Gardens. (Pictured) This cultivar combines dark purple to black leaves with swirled pale and dark pink flowers.  It has performed very well in my landscape and if I could only grow one, this might be it.
  • ‘Lord Baltimore.’ The classic, large growing cultivar with bright red flowers that is widely available and easily found.  An oldie (introduced in 1955) but a goodie.
  • ‘Midnight Marvel’ by Walter’s Gardens. A “hot off the press” new cultivar that is currently difficult to find due to popularity, though some online outlets have them available in small sizes.  This one is worth your patience.  Sporting deep red blooms on near black foliage, there’s nothing else like it in the landscape.

In addition to being gorgeous plants, Rose Mallows are extremely versatile in the landscape and could not be easier to grow.  Because the size varies so greatly (from the diminutive 30” tall ‘Luna’ series to the 8’ tall unimproved species), there really is a place for one in every garden.  I like to use the smaller cultivars in large containers to facilitate moving them around where their floral display has the greatest impact or to create a tropical effect where in ground plantings are not an option (pool decks, patios, etc).  The larger cultivars make spectacular specimen plantings in perennial and shrub beds and even make a really dense, striking hedge (just know they disappear in the winter).  Be sure to give them as much sun as possible, as this will enhance the number of flowers on each plant and darken the foliage on the cultivars with purplish/black leaves.  Too little sun will result in fewer flowers and lighter green foliage.  As wetland plants, Rose Mallows enjoy regular water, either from rainfall or irrigation; they will let you know when they need it – their large leaves readily wilt under drought stress, somewhat like Hydrangea.

For low-maintenance, native, pollinator friendly, cold-hardy tropical color, you need look no further than Rose Mallow.  These perennial shrubs come in all sizes and colors and fit any landscape!  Look for the above listed series and cultivars at better garden centers and online retailers and enjoy the oohs and ahhs elicited when people first get a glimpse of Hardy Hibiscus in your landscape!  Happy Gardening!

 

The Grass is Getting “Hungry”

The Grass is Getting “Hungry”

(UF/IFAS photo Thomas Wright)

Northwest Florida’s weather patterns can present challenges to maintaining a health lawn. Heavy rains promote fast growth and relentless sunshine causes lawns to fade.  In the last 200 days we have received at least 68 days of rain.  While the rest of Florida was experiencing record drought, the Panhandle was experiencing torrential downpours.  With every drop of rain your spring fertilizer is being metabolized by the lawn, reducing how many nutrients remain in the soil.  Even the best slow-release fertilizer will only last 3-4 months.  The message is: “It’s time for more fertilizer.”

A healthy lawn is an important component of the urban landscape. Not only do lawns increase the value of a property, they also reduce soil erosion, filter stormwater runoff, cool the air, and reduce glare and noise.  A healthy lawn effectively filters and traps sediment and pollutants that could otherwise contaminate surface waters and groundwater.  Lawns require nutrients throughout the growing season to stay healthy.  In Northwest Florida the growing season is typically April to October.

Proper fertilization consists of selecting the right type of fertilizer and applying it at the right time and in the right amount for maximum plant uptake. The type of fertilizer should be based on a soil test, available through UF/IFAS Extension. The timing of application and amount of fertilizer is dependent on the research-based recommendations for the grass species and the fertilizer analysis of the product being used.

Chart excerpted from Florida Friendly Landscaping publication

Select only a fertilizer that states that the product is for use on residential turf. Do not use a fertilizer meant for flower or vegetable gardens on lawns. By Florida Administrative Code, Rule 5E-1.003, the Urban Turf Rule requires that the fertilizers being applied to residential lawns are labeled for the site and the application rates be followed.  Typically, these products will contain both slow-release nitrogen and low or no phosphorus.  Slow-release nitrogen will provide a longer-lasting response from the grass and reduces the potential for burning. For more information on the Urban Turf Rule go to: http://www.edis.ifas.ufl.edu/pdffiles/EP/EP35300.pdf.

With frequent rain the soil is also losing iron. Keep in mind that the green fading to yellow appearance in your lawn may be an iron deficiency.  Before applying your summer fertilizer put out a liquid chelated iron.  It will improve the health of the lawn while you are trying to find a dry day to fertilize.  While it is necessary to water in fertilizer with ¼” of water to reduce burn potential and volatilization, never apply fertilizer when heavy rain is expected.  The rainfall over ¼” can encourage runoff and/or leaching of that fertilizer, which can be costly and environmentally harmful.

Mowing Your Lawn Correctly

Mowing Your Lawn Correctly

Northwest Florida has experienced an enormous amount of rain this summer. The western panhandle has received over 29 inches of rain since the beginning of May according to the Florida Automated Weather Network station at the West Florida Research and Education Center in Jay, Florida. That is 44% of average annual rainfall in less than two months. All of this rain has probably thrown off the normal lawn mowing routine. It is hard to get out and mow the lawn when its pouring buckets or the lawn resembles a swamp. With all of this in mind, there are a couple of mowing pointers that would be useful to implement to address the out of control lawn growth and the challenges posed by not being able to stick to normal mowing schedule.

  • Always attempt to mow at the IFAS recommended height for your species of turfgrass. The recommended heights are determined by how quickly the species grow in our climate. The chart below shows the best heights at which to mow your lawn. The fine textured zoysiagrasses are not listed but should be mowed at 0.5 to 1.5 inches. Check the lawn mowers mowing height by measuring the distance from the ground to the bottom of the mowing deck on a flat surface.

From Mowing Your Florida Lawn: http://edis.ifas.ufl.edu/pdffiles/LH/LH02800.pdf

  •  When you do get out to mow, never remove more than 1/3 of the leaf blade. If you cut to short you will “scalp” the turf and cause a brown look on the lawn. This can be damaging to the turf and allow for weeds to get established by exposing the soil to the sunlight. What is taking place more in northwest Florida is not mowing frequently enough and cutting off excess growth due to the rain. This also can cause scalping so it is very important to mow frequently enough to only remove 1/3 of the leaf blade.

A zoysia lawn that has been “scalped” after excess growth and infrequent mowing. (Photo Credit: Blake Thaxton)

Other practices such as keeping your mower blade sharp, mowing in different directions, and leaving clippings on the ground will help keep a healthy Florida lawn. Please see more information about mowing correctly in Florida in the University of Florida/IFAS Extension publication: Mowing Your Florida Lawn

Algal Leaf Spot Common on Magnolias and Camellias

Algal Leaf Spot Common on Magnolias and Camellias

Algal leaf spot, also known as green scurf, is commonly found on thick-leaved, evergreen trees and shrubs such as magnolias and camellias.  It is in the genus Cephaleuros and happens to be one of the only plant parasitic algae found in the United States.  Although commonly found on magnolias and camellias, algal leaf spot has a host range of more than 200 species including Indian hawthorn, holly, and even guava in tropical climates.  Algal leaf spot thrives in hot and humid conditions, so it can be found in the Florida Panhandle nearly year round and will be very prevalent after all the rain we’ve had lately.

Symptoms

Algal leaf spot is usually found on plant leaves, but it can also affect stems, branches, and fruit. The leaf spots are generally circular in shape with wavy or feathered edges and are raised from the leaf surface. The color of the spots ranges from light green to gray to brown.  In the summer, the spots will become more pronounced and reddish, spore-producing structures will develop. In severe cases, leaves will yellow and drop from the plant.

Algal Leaf Spot

Algal leaf spot on a camellia leaf. Photo Credit: University of Florida/IFAS Extension

The algae can move to the stems and branches in more extreme cases. The algae can infect the stems and branches by entering through a small crack or crevice in the bark. The bark in that area cracks as a canker forms that eventually can girdle the branch, killing it.

Algal Leaf Spot on a Stem

Algal leaf spot on a sycamore branch. (Platanus occidentalis). Photo Credit: Florida Division of Plant Industry Archive, Bugwood.org.

Management

In most cases, algal leaf spot is only an aesthetic issue. If only a few leaves are affected, then they can just be removed by hand.  \It is important that symptomatic leaves are discarded or composted offsite instead of being left in the mulched area around the trees or shrubs. If symptomatic leaves are left in the same general area then irrigation or rain water can splash the algal spores on healthy leaves and branches. Infected branches can also be removed and pruned.

Preventative measures are recommended for long-term management of algal leaf spot. Growing conditions can be improved by making sure that plants receive the recommended amount of sunlight, water, and fertilizer. Additionally, air circulation around affected plants can be increased by selectively pruning some branches and removing or thinning out nearby shrubs and trees. It is also important to avoid overhead irrigation whenever possible.

Fungicide application may be necessary in severe cases. Copper fungicides such as Southern Ag Liquid Copper Fungicide, Monterey Liqui-Cop Fungicide Concentrate, and Bonide Liquid Copper Fungicide are recommended. Copper may need to be sprayed every 2 weeks if wet conditions persist.

Algal leaf spot isn’t a major pathogen of shrubs and trees, but it can cause significant damage if left untreated. The first step to management is accurate identification of the problem.  If you have any uncertainty, feel free to contact your local Extension Office and ask for the Master Gardener Help Desk or your County Horticulture Agent.

Tree Care in Hurricane Season

Hurricane Season began June 1. While storm experts are predicting a slower year due to El Nino conditions, it only takes a single storm landing nearby to cause millions in damage, uprooting trees and lives.

Tree damage to homes and property can be devastating, and one of the first instincts of many homeowners when they see a big storm in the Gulf is to start trimming limbs and removing trees.  However, it is wise to fully evaluate one’s landscape before making an irreversible decision. Trees are crucial for providing shade (i.e. energy savings), wildlife habitat, stormwater management, and maintaining property values.

Downed trees in a row along a hurricane-devastated street. Photo Credit: Mary Duryea, University of Florida

Downed trees in a row along a hurricane-devastated street. Photo Credit: Mary Duryea, University of Florida

University of Florida researchers Mary Duryea and Eliana Kampf have done extensive studies on the effects of wind on trees and landscapes, and several important lessons stand out.  Keep in mind that reducing storm damage often starts at the landscape design/planning stage!

  • Select the right plant for the right place.
  • Post-hurricane studies in north Florida show that live oak, southern magnolia, sabal palms, and bald cypress stand up well compared to other trees during hurricanes.  Pecan, water and laurel oaks, Carolina cherry laurel and sand pine were among the least wind resistant.
  • Plant high-quality trees with strong central trunks and balanced branch structure.
  • Longleaf pine often survived storms in our area better than other pine species, but monitor pines carefully. Sometimes there is hidden damage and the tree declines over time. Look for signs of stress or poor health, and check closely for insects. Weakened pines may be more susceptible to beetles and diseases.
  • Remove hazard trees before the wind does. Have a certified arborist inspect your trees for signs of disease and decay. They are trained to advise you on tree health.
  • Trees in a group (at least five) blow down less frequently than single trees.
  • Trees should always be given ample room for roots to grow.  Roots absorb nutrients, but they are also the anchors for the tree. If large trees are planted where there is limited or restricted area for roots to grow out in all directions, there is a likelihood that the tree may fall during high winds.
  • Construction activities within about 20 feet from the trunk of existing trees can cause the tree to blow over more than a decade later.
  • Plant a variety of species, ages and layers of trees and shrubs to maintain diversity in your community
  • When a tree fails, plant a new one in its place.

 

Learning from the Floods

Learning from the Floods

Just over a year ago, southwest Alabama and northwest Florida experienced a devastating storm that left hundreds without access to their homes and businesses, flooded out and stranded by a hurricane-force storm that didn’t come with the luxury of a week’s warning. Rainfall records in Pensacola go back to 1879, and the April 29-30 storm broke them all, estimating just over 20 inches over the two days. Not only was the rainfall heavy, but the torrent was high in both velocity and volume—at one point, a mind-boggling 5.68 inches fell in the span of one hour. That’s half the annual rainfall of many cities in California and Texas!

gas geysers

A residential street in Pensacola became a raging river a year ago during the torrential floods, putting dozens of people out of their homes. Photo credit: Carrie Stevenson UF/IFAS Extension.

With every dark storm cloud comes a silver lining, though, and just like the millions pumped into our regional economy from oil spill-related fines, the April 2014 floods have awakened a “greener” ethic among many residents, business owners, and politicians. According to a study just released by an environmental consulting firm, when asked about infrastructure changes and improvements to flooding and stormwater, attendees at community meetings overwhelmingly preferred “low impact” solutions such as expanded green space, cisterns, rain gardens, and stream restoration to “hard” structures such as bigger underground pipes and more pumps. While traditional engineering infrastructure is still crucial to a community that must maintain roads, stormwater ponds, and buildings, I find it encouraging that residents are interested in trying different techniques that have proven successful both here and in other parts of the world.

rain barrel

The new Langley Bell 4-H Center has four large rain barrels around the building, used to collect roof runoff for landscape design. Photo credit: Carrie Stevenson UF/IFAS Extension.

So, how does one prepare for unexpected rain and floods? The first thing is to realize that northwest Florida receives the most annual rainfall (over 60”) of any region of the state, and sometimes it seems to come down all at once.  Preparing landscapes to handle both frequent and heavy rains is an important place to start.  This article will begin a series of articles delving into those “low-impact” stormwater management techniques that can help lessen the impact of the intense storms we experience here in northwest Florida. Many of these practices, such as creating mulch pathways, harvesting rainwater, and installing shoreline vegetative buffers, can be implemented by individual homeowners and help reduce the impact of flooding on a neighborhood and city-wide level