Tree dieback is a complex syndrome and slow developing. Dieback is essentially a process in which trees lose leaves and limbs. This usually occurs as a result of severe stress to the tree’s bark or root system, but could be a result of a declining life cycle.
It’s important to note that there is a significant balance between a tree’s root system and the number of leaves and limbs it can support. For example, if a tree loses part of its root system, possibly due to disease or lawn equipment damage, the tree will forfeit a portion of its leaves. Dieback doesn’t happen overnight, though. It’s a slow process, with larger trees taking much longer time for signs of stress to emerge. However, a large tree root system is very sensitive to damage, whereas a small tree will adapt quickly and is much more resilient to damage. So, what can be done to prevent dieback in trees?
First and foremost, trees, like all living things, have a natural life cycle. Regardless of how you care for your trees, dieback will occur. The most important management measure in extending the life of a tree is to protect the root system and bark.
With each passing year, a tree grows new bark in the rejuvenation process. The bark replacement process inevitably becomes more difficult as the tree gets older and in turn the tree is more and more susceptible to dieback. If the bark becomes damaged, especially later in the tree’s life cycle, then fungi and insects have a much greater chance to cause serious harm. Treating bark damage with a wound dressing to prevent decay is the recommended procedure.
Lichens come in many forms and are commonly blamed for the decline and death of trees and shrubs, however they do not cause harm. Credit. Sydney Park Brown and Joseph Sewards, UF/IFAS.
A common misconception is that epiphytes, such as lichens and Spanish moss, are tree diseases. Epiphytes are known as “air plants” and thrive in the Panhandle. They survive on moisture and nutrients in the atmosphere and are harmless to trees. However, a tree that becomes inundated with epiphytes may be an indicator of excessive soil moisture, which may lead to root rot.
Lawn weed killers can have detrimental effects to trees, even if the application seems to be from a safe distance. When using a weed killer near a tree’s root system, confirm on the label that the product is designed to kill green growth only. It can’t be overstated that excessively fertilizing an old tree will greatly accelerate the decline of the tree. Some may think this will stimulate a tree and extend its life, but instead it will do the opposite. Young trees can tolerate fertilizer applications, as they need crown growth. Older trees will simply become top heavy, and structural damage will likely occur.
Don’t forget, trees need space too. A mature tree forced to occupy a small space will simply not adapt. Be sure to have adequate spacing when planting younger trees and shrubs in the vicinity of older trees. Also, keep your trees pruned away from touching structures and utilities.
Tree dieback is a complex issue to manage. By following these measures, you can help extend the life of your trees and continue to have a picturesque landscape.
For more information on tree dieback, contact your local county extension office.
Please visit Florida Friendly Landscaping, http://fyn.ifas.ufl.edu/, for more information on maintaining your landscape.
For more general information on lichens, please see UF/IFAS EDIS document “Spanish Moss, Ball Moss and Lichens-Harmless Epiphytes” by Joe Sewards and Dr. Sydney Park Brown: https://edis.ifas.ufl.edu/pdffiles/EP/EP48500.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
Every so often while I am enjoying a walk through the garden, I notice a growth pattern on a plant that is just not normal. One of the more interesting patterns I see is called fasciation. This is a distortion of plant tissue that often causes flattened, curved, or the thinning of plant tissues. I recently noticed this on the stem of a Coral Porterweed in the Escambia County Demonstration Garden. The leaves were a normal shape but several inches of the stem were flattened and curved.
The distorted stem tissue of a Coral porterweed. Photo by Beth Bolles, UF IFAS Extension Escambia County.
So what is causing this type of growth pattern?
The most common cause of fasciation is usually some type of genetic mutation in the growing points of the plant. The other possible causes could be a physical injury to new tissues, a bacterial infection, chemical injury, or even an insect injury. Fasciation will be random in its occurrence and many gardeners may never have it occur on a plant in their yard. I have seen it on both woody and herbaceous plants in my own yard and in the demonstration gardens.
If you see a plant exhibiting this distortion of growth, you don’t need to take any action. If the growth is unsightly to you, prune out the affected plant tissue. It is probably best that you not propagate material from an affected plant just to prevent any transfer of the distortion to a new plant if the cause is genetic or from a living organism.
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!
‘Stellar Ruby’ is a new purple-flowered hybrid banana-shrub that will soon be released nationally
You just learned about a fabulous new plant, and you HAVE to have it. How can you acquire this rare treasure?
Many of us gardeners have experienced this desire for a “new” plant but have quickly become frustrated with trying to locate and buy that particular plant. It’s not easy, or else that plant wouldn’t be new or rare, but the four P’s outline a few strategies for satisfying a “new” plant passion: plant societies, plant institutions, patience and payment.
Plant societies are one of the best avenues for acquiring new plants. Most plant societies consist of members with intense interest in particular plants or plant groups, so find the society that supports the plant that interests you. Plant society members often include breeders or plant explorers who introduce new plants. Whether magnolia or camellia or conifers or other plants, membership in such societies can give you a leg up on learning about, seeing, and accessing new plants. Consequently, fellow society members are often the first to acquire the newest plants, and that could be you!
Beyond this, participation in generalist plant groups can also give you unexpected benefits of networking with like-minded people. Thus, don’t overlook groups like Master Gardeners, garden clubs, or garden/park support groups. Their members often include passionate plant people like you who may have more connections (or special plants) than you realize.
Similarly, plant institutions such as universities or botanic gardens are another way to learn about and acquire new plants. These institutions often hold plant sales or fund-raising plant auctions that include new, unusual or rare plants. Online plant sales or auctions are becoming more common, so distance is less of an obstacle than it used to be. However, these institutions are less focused on particular plants, so it may be hit-or-miss to find that particular plant you want. To increase the chances of finding your desired plant, contact these institutions and ask to be notified about these events. You may even find a plant you didn’t know you wanted!
Patience is a virtue when trying to acquire new plants. Some plants take a long time to propagate or are not easy to propagate or grow. If you have the patience to wait, many plants will become more available – – – and at a more reasonable cost – – – as nursery production catches up to demand.
Finally, “payment”: let’s face it, money talks! If you have the funds, you can usually find the means to acquire the plants you desire. Most new or rare plants usually enter the market through specialty nurseries, operations that often maintain their own breeding or plant exploration programs or have exclusive arrangements with those who do. This is an expensive means of obtaining new plants, and therefore these specialty nurseries rightly charge more for their plants.
Another way money works to your advantage is the ability to travel. Many specialty nurseries, collectors, etc. often aren’t found in our part of Florida. If you can travel to these nurseries, botanic gardens, etc., it will be much easier to acquire unusual plants. If you can’t afford special trips to these sites, consider taking vacations to areas near these specialty nurseries, or to areas where these specialty nurseries are “on the way” to your vacation destination.
It goes without saying that you should learn about a “new” plant as much as possible before investing in an extensive hunt. Simple internet searches should tell you if that plant will be adapted to the climate and soil of your garden. At the other extreme, check resources like the IFAS Assessment (https://assessment.ifas.ufl.edu/) to make sure that particular plant won’t become invasive in your region of Florida.
Gardening is a very fulfilling activity, and the excitement of “new” plants just makes gardening more fun! Happy hunting!
Photos by Sheila Dunning
The showy chaste tree makes an attractive specimen as the centerpiece of your landscape bed or in a large container on the deck. Much more of them are being seen since the Florida Department of Transportation has recognized the tree as a desirable median planting. Easy-to-grow, drought resistant, and attractive to butterflies and bees, Vitex agnus-castus is a multi-stemmed small tree with fragrant, upwardly-pointing lavender blooms and gray-green foliage. The chaste tree’s palmately divided leaves resemble those of the marijuana (Cannabis sativa) plant; its flowers can be mistaken for butterfly bush (Buddleia sp.); and the dry, darkened drupes can be used for seasoning, similar to black pepper, making it a conversation piece for those unfamiliar with the tree.
Vitex , with its sage-scented leaves that were once believed to have a sedative effect, has the common name “Chastetree” since Athenian women used the leaves in their beds to keep themselves chaste during the feasts of Ceres, a Roman festival held on April 12. In modern times, the tree is more often planted where beekeepers visit in order to promote excellent honey production or simply included in the landscape for the enjoyment of its showy, summer display of violet panicles.
Chaste tree is native to woodlands and dry areas of southern Europe and western Asia. It will thrive in almost any soil that has good drainage, prefers full sun or light shade, and can even tolerate moderate salt air. Vitex is a sprawling plant that grows 10-20 feet high and wide, that looks best unpruned. If pruning is desired to control the size, it should be done in the winter, since it is a deciduous tree and the blooms form on new wood. The chaste tree can take care of itself, but can be pushed to faster growth with light applications of fertilizer in spring and early summer and by mulching around the plant. There are no pests of major concern associated with this species, but, root rot can cause decline in soils that are kept too moist.
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/
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
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
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
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
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
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