by Beth Bolles | Sep 8, 2016
By the look of the crowded nurseries during March and April, springtime seems to be the best time for planting. This is the case for our frost tender annuals and perennials but we are actually heading into our best seasons for planting trees and shrubs.
The fact that above ground portions of trees and shrubs go through a time of slowed growth or dormancy is the good reason for planting during the fall and winter. Although we don’t see it, roots are still growing slowly and the upcoming months give new plants the time for roots to spread into surrounding soil before hot temperatures return. Water stress is also not as significant during the cooler months. Plants still need to be supplied regular water but needs are not as high, especially if rainfall occurs.
A tree installed in the cooler months has more time to establish before hot weather returns.
Start gathering your ideas for new or replacement trees and shrubs that will match your landscape and visit a local nursery this Fall.
If you need an update on tree and shrubs planting and care techniques read more in the UF IFAS publication.
by Mark Tancig | Jul 5, 2016
When you don’t know what’s ailing your plant, ask an expert.
Many gardeners get stumped when a favorite plant of theirs comes down with a strange “something”. Many of these gardeners know about UF/IFAS Extension and call their local horticulture and agriculture agents for assistance in figuring out what’s going on. However, even these experts are often stumped by what they see. Fortunately, the agents have another layer of experts to fall back on. In addition to the resources in Gainesville, we have the Plant Disease Diagnostic Clinic, located at the North Florida Research Center in Quincy. Plant pathologists here can help determine what fungus, bacteria, virus, or viroid may be the problem.
Plant pathologists are basically plant doctors. They use all sorts of sophisticated techniques to determine what is the cause of a particular plant problem, from growing out fungal spores to examining DNA. Not only do these plant doctors tell us what the ailment is, they also provide recommended cures, or control options. They are also doing research to prevent different diseases from taking hold in our area and reduce the impact on our local growers.
Plant pathologist at work!
At a recent workshop in Quincy, we learned that plant pathology researchers are working on a fungus that affects watermelons, virus and bacteria that can wipe out a farmer’s tomato crop, and a virus that could impact our local roses. Working as a team of scientists, they study these pathogens in the lab and conduct controlled field experiments to figure out which techniques are most effective. Some of this research is leading to different methods and/or products that can help growers and gardeners alike keep their fields and landscapes healthy.
So, if your plants have problems, please contact your local Extension Office. If they don’t know the answer, then the network of scientists, including plant pathologists, in the UF/IFAS Extension family can be called on for backup to provide you with the best possible answer.
by Larry Williams | May 12, 2016
Do you have azaleas or camellias with leaves that are thickened, curled and waxy in appearance? This is fairly common this year and is caused by a fungus.
Camellia leaf gall on Sasanqua Camellia. Note swollen, malformed leaves. Photo credit: Larry Williams
Exobasidium vaccinii is a fungus that causes leaves, and in some cases flower petals, to enlarge abnormally and is commonly referred to as azalea leaf and flower gall.
Infected azalea and camellia leaves become large and distorted. Eventually a white powder covers the galls. The white growth consists of spores, which is how the fungus reproduces. Galls ultimately turn brown and harden. Not every leaf will be infected.
The disease relies on airborne spores produced in the whitish mold on the surface of galls in late spring to early summer to reproduce. Some plant pathologists believe that once the spores are released, they are blown and washed to leaf and flower buds where they cause new infections. Galls then form the following spring. Other plant pathologists think that the spores are produced the following year from the old dried, brown galls that fell to the ground around infected plants the previous year. In spring, the spores blow and splash onto new leaves and petals as they emerge causing infection. One or both lines of thought may be true. But in either case, it’s important to remove and dispose of infected leaves before they turn white with spores.
Once you see evidence of infected leaves, it’s too late for chemical control. Besides, there currently is no effective or practical fungicide to control this disease in home landscapes. But you can reduce the amount of infection the following year by pruning infected leaves and throwing them away before spores develop. After removing infected leaves with galls, never leave them on the ground around the plants.
It’s best to bury, burn or place infected leaves in a plastic bag and throw them away. This disease is more severe during a cool, wet spring, which we experienced this year. It’s advisable to not add to the problem by artificially providing the “wet weather” the spores need by frequently using an overhead sprinkler and keeping the foliage wet in the spring during disease development. This is exactly what this and many other plant diseases need – wet conditions. It’s best to water established landscape plants on an as needed basis.
In the home landscape, the fungus does not cause any long-term problems for the plant. It just makes the plant’s leaves look ugly. Infected leaves will usually fall prematurely.
by Daniel J. Leonard | Apr 27, 2016
People are, by nature, skeptical. Humans are and have always been questioners of the world around them and that’s a good thing! For instance, when one reads a sensational article on Facebook or watches an infomercial selling a too-good-to-be-true product he/she is immediately dubious of the veracity of the claim. Given this innate sense, why do consumers take plant tags displayed on retail plants and the information listed there as infallible fact when in reality they are often full of hyperbole and misleading?
I do not mean to insinuate that nurseries and landscape professionals are intentionally leading consumers astray. They are not. However, there is much incorrect information disseminated to consumers by the green industry on plant fact sheets. Take my titular example, ‘Little Gem’ magnolia is widely advertised and sold as a “dwarf” magnolia, only growing 15’-25’ tall. If given proper care, it will grow to that height…in seven to ten years. Given enough time, ‘Little Gem’ has will grow in excess of forty feet. People plant this cultivar under the eaves of single story houses on a regular basis! I promise that cute little magnolia you were told would grow 15’ tall will look rather silly when it is four times the height of your house. Take another example, how many times have you seen or heard of ‘Acoma’ crapemyrtle being sold as a “semi-dwarf” cultivar that grows to 10’ in height for use in a tight spot of the landscape in lieu of the much larger ‘Natchez’? It will fill that tight spot and fill it rather quickly. ‘Acoma’ can easily reach 20’ in height and width at maturity, engulfing its intended area.
Typical plant tag. Notice the “Average Size” section. This is where consumers should use discretion.
So why does this happen? Why are plant tags so often mistaken? There are two primary reasons that correct mature sizes are not given. First, in the competitive world of plant breeding and introduction where there can be hundreds or thousands of cultivars of a single species, it is of utmost importance to introduce plants as quickly. Quick introduction is necessary because others are probably working to find similar traits; therefore, if one notices that a plant possesses a drastically different flower, flowering pattern, leaf shape, leaf size, or growth habit, the plant is often rushed to market. This leaves little time for complete trials of the plant to see what it would look like at maturity.
Secondly, most well-adapted or native trees/shrubs have relatively long life spans. A crapemyrtle or magnolia can easily grow and thrive in a landscape for thirty years or more before reaching maximum size. Nurseries simply do not have time to evaluate plants that long. Many nurseries, due to vagaries of economic cycles and length of career spans, don’t even exist for thirty years much less trial a single plant for that length of time!
In conclusion, nurseries are not likely to change their plant tag practices, but there are a couple of checks consumers can use to make sure they buy an appropriate plant for the scale of their site. First, it is a good rule of thumb to double the advertised plant height to arrive at a better idea of the plant’s mature size. Second, drive through established neighborhoods and observe what certain plants look like in a mature landscape. This will give one an idea of what the plant is capable of. The third and best option is to consult your local County Extension Office. They will be able to offer research-based information to help you make the right decision in your plant choices. Keep this in mind the next time you are thinking of buying the latest, greatest plant at your local nursery!
Happy Gardening!
by Mary Salinas | Apr 21, 2016
Recently, a home gardener brought in some strange looking new leaves on his camellia. The youngest leaves were thick and fleshy and looked more characteristic of a succulent type plant than a camellia. What’s wrong with these leaves?
Camellia leaf gall infection resulting in fleshy light green and pink leaves. Note the contrast with a healthy uninfected leaf. Photo credit: Mary Derrick, UF/IFAS.
The culprit is a fungus Exobasidium camelliae whose spores are carried by the wind in search of camellias. This fungus infects camellias, especially sasanquas; it will not infect any other plant species. The disease it causes is known as camellia leaf gall and is most commonly seen here in the Florida panhandle in April. The frequent wet weather this winter and spring created favorable conditions for disease development.
The symptoms of the disease are easy to distinguish and really stand out against the typical dark green leaves of the camellia. Leaves become thick and fleshy and the color ranges from light green to cream to pink. As the disease progresses and the galls mature, the lower leaf surfaces of the leaves will peel away to reveal a white underside laden with fungal spores. Wind and rain will take these new spores to other parts of the camellia or other camellias in the vicinity where they will lay dormant and cause infection the following spring. Eventually the galls will turn brown and dry up.
The underside has pealed away revealing white fungal spores. Photo credit: Mary Derrick, UF/IFAS Extension.
Camellia leaf gall is not a serious disease that requires chemical intervention for the homeowner. Simply remove the galls and put them in the trash. The earlier you remove the galls the better; the risk of further infection can be reduced if the galls are removed before the undersides peel and expose their spores. Any that have fallen to the ground can spread the disease and need to be removed.
For more information:
Camellias at a Glance
Camellia Leaf Gall
by Sheila Dunning | Apr 21, 2016
Mountain laurel. Photo credit: Sheila Dunning, UF/IFAS Extension.
If you are lucky enough to live on the southern Alabama edge of northwest Florida, you may want to see if you can find mountain laurel blooming now near the wooded creeks. Its native range stretches from southern Maine south to northern Florida, just dipping into our area. The plant is naturally found on rocky slopes and mountainous forest areas. Both are nearly impossible to find in Florida. However, it thrives in acidic soil, preferring a soil pH of 4.5 to 5.5 and oak-healthy forests. That is something we do have. The challenge is to find a cool slope near spring-fed water.
Mountain laurel blooms. Photo credit: Sheila Dunning, UF/IFAS Extension.
Mountain laurel (Kalmia latifolia) was first recorded in America in 1624, but it was named after Pehr Kalm, who had collected and submitted samples to Linnaeus in the 18th century. The wood of mountain laurel was popular for small household items. It is heavy and strong with a close, straight grain. However, as it grow larger it becomes brittle. Native Americans used the leaves as an analgesic. But, all parts of the plant are toxic to horses, goats, cattle, deer, monkeys and humans. In fact, food products made from it, including honey, can produce neurotoxic and gastrointestinal symptoms in people consuming more than a modest amount. Luckily, the honey is usually so bitter that most will avoid eating it.
Mountain laurel in its native habitat. Photo credit: Sheila Dunning, UF/IFAS Extension.
One of the most unusual characteristics of mountain laurel is its unique method of dispersing pollen. As the flower grows, the filaments of its stamens are bent, creating tension. When an insect lands on the flower, the tension is released, catapulting the pollen forcefully onto the insect. Scientific experiments on the flower have demonstrated it ability to fling the pollen over 1/2 inch. I guess if you don’t taste that good, you have to find a way to force the bees to take pollen with them.
The mountain laurel in these pictures is from Poverty Creek, a small creek near our office in Crestview. This is their best bloom in 10 years. Maybe you can find some too.
Native range of mountain laurel.
