by Mary Salinas | May 5, 2016
The panhandle of Florida is a great place to grow citrus with our plentiful sunshine and sandy soil. But some varieties do better than others. Here are some that thrive in the more northerly climes of Florida:
Nagami kumquat. Photo credit: UF/IFAS.
- Satsuma mandarin is cold hardy to 15°F once established. There are a few different available cultivars with fruit ripening October through December. Fruit needs to be picked promptly when ripe.
- Kumquat is cold hardy to 10°F once established. ‘Nagami’ and ‘Meiwa’ are the two common cultivars of the small tart fruits. Fruit matures in fall and winter and holds fairly well on the trees.
- Calamondin is a lesser known variety that bears small fruit that resemble tangerines. The tart fruit is great for jams and chutneys. Fruit is borne all year.
- Some of the sweet oranges that do well in the panhandle are Navel, Hamlin and Parson Brown. They are cold hardy to 14°F once established and are harvested November through January.
- Minneola or Honeybell tangelo is also hardy to 14°F and harvested in January. This is a cross between a Duncan grapefruit and a Darcy tangerine. This bell-shaped fruit is very juicy and sweet. Unlike the other citrus varieties, it needs another citrus nearby for cross-pollination in order to produce an abundant crop.
- Meyer Lemon is the choice to make if you would like to grow lemons in the panhandle. Other lemons may be damaged by our occasional freezes.
Grapefruit and lime can be grown – although unreliably – on the coast with protection from northwestern winter winds. They are much more susceptible to freezes in more northerly panhandle locations.
In order to have the healthiest and most productive trees, learn about how to properly care for citrus and how to recognize and combat the pests and diseases that occur.
Citrus canker symptoms on leaves, fruit and stem. Photo by Timothy Schubert, FDACS
There are threats to our dooryard and commercial citrus from pests and disease. Only vigilance will help to combat the challenges so that we may continue to grow and enjoy our citrus. What can we do to protect our citrus?
- Report any serious diseases like suspected citrus canker or citrus greening to the Division of Plant Industry by calling toll-free 1-888-397-1517. Inspections and diagnosis are free. Citrus canker has been confirmed in south Santa Rosa County in the past 3 years.
- Purchase citrus trees only from registered nurseries – they may cost a little more but they have gone through an extensive process to remain disease and pest free. That will save you $$ in the long run!
- Don’t bring plants or fruit back into Florida – they may be harboring a pest!
- Citrus trees or fruit cannot move in or out of the State of Florida without a permit. This applies to homeowners as well as to the industry. This rule protects our vital dooryard trees and citrus industry.
For more information please see:
Save Our Citrus Website
UF IFAS Gardening Solutions: Citrus
Citrus Culture in the Home Landscape
UF IFAS Extension Online Guide to Citrus Diseases
Your Florida Dooryard Citrus Guide – Common Pests, Disease and Disorders of Dooryard Citrus
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 Ray Bodrey | Apr 22, 2016
You could certainly argue that the azalea bloom is the symbol of the southeast during spring time. This time of year, yards across the panhandle explode with vibrant colors of this unmistakable flower bloom. Even though Florida’s azalea plants put on a spectacular flowery show, most of us pay very little attention to their management at this time of year. However, the kind of care azaleas receive in late spring and summer can have an effect on the bloom production for next season. There are some management measures that can be done during this time to ensure that you have a bountiful azalea bloom next spring.
Credit. Carolyn Wildes, UF/IFAS.
Chlorosis, a condition that causes leaves to produce insufficient chlorophyll, is the most common problem with azaleas this time of year. Fortunately, this is easy to recognize and correct. Chlorosis shows up as yellowing in between the veins of leaves, the veins stay dark green. It’s caused by lack of available iron in the soil.
To correct chlorosis, add aluminum sulfate to the soil. The addition of ¼ to a ½ pound per square yard of soil surface should suffice. Broadcast the aluminum sulfate over the soil surface and add a layer of mulch. It’s important to remember that you should not apply aluminum sulfate more than once a year. More applications will cause detrimental effects to the plant. Other chemicals that are useful in correcting iron chlorosis in azaleas are ordinary agricultural sulfur, ferrous sulfate and chelated iron compounds. Each of these chemicals have different application directions, so be sure to read the labels for direction of use.
Proper watering is also imperative. Generally, established plants should receive ¾ – 1 inch of water every 10 days to 2 weeks during dry periods to wet the soil to a depth of 10-12 inches. When the weather is hot and dry, azaleas need soil saturation in the root zone once a week. Azaleas have shallow feeder roots that dry out very quickly if the soil is dry. Remember, soil with a sufficient amount of organic matter holds moisture better than sandy soils, and will require less watering. Also, a mulch layer helps to reduce evaporation and keep the soil cool and moist.
Pruning your plants should be done in late spring. If you prune later in the year, there’s a good chance you may reduce or eliminate flowers for next year. Usually it’s best to prune right after flowering.
As for fertilizer applications, frequent and light applications are necessary in Florida’s sandy soils. Acid-forming fertilizers like 12-4-8, 15-0-15 or ammonium sulfate should be applied in all four seasons. Apply approximately ¼ pound to a mature plant, or ¾ to 1 ½ pounds per 100 square feet.
Following these recommendations will help secure your rich bloom season for next year.
For more information please see:
Azaleas at a Glance
Florida-friendly Landscaping
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.
by Matt Lollar | Apr 14, 2016
Scales on a Chinese Elm.
Scales on a Chinese Elm.
Last week as I was basking in the shade of the Chinese Elms (Ulmus parvifolia) in my yard, I noticed some strange lumps on the twigs. Upon further investigation, I realized the “lumps” were scales. Scale insects are serious pests of a number of ornamental plants. Here in Florida there are 13 different families of scales with the most common being armored scales, soft scales, and mealybugs. Scales have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental plants. Heavy infestations cause extensive leaf yellowing, premature leaf drop, branch dieback, and eventually plant death.
Scale Biology
The life cycle of a scale begins with eggs being laid beneath wax coverings or beneath the adult female. Eggs typically hatch in 1 to 3 weeks. The newly hatched nymphs, called crawlers, move around a plant until they find a spot to feed. Once a feeding site is located, their piercing sucking mouthparts are inserted into the plant and the crawlers begin to feed and grow. The males of many scale species develop wings as adults and fly to other plants to reproduce.
The magnolia white scale. Credits: University of Florida
Armored Scales
Armored scales get their armor by secreting a waxy covering over their bodies that is not attached. The scale lives under this covering and uses it as a protection to feed under. Armored scales can be almost any color or shape and range anywhere from 1/16 to 1/8 inch in diameter. For females, these shapes range from circular to oval to long and slender. The males typically have coverings that are more elongate and smaller than the females. As adults, the males are tiny, winged, gnat-like insects and are rarely seen.
Hemispherical scale on coontie. Credits: Lyle Buss, University of Florida
Soft Scales
Similar to armored scales, soft scales secrete a waxy covering, but it is attached to their bodies. Soft scales can be a number of colors, shapes, and sizes and range anywhere from 1/8 to 1/2 inch in diameter. Their shapes vary from spherical to nearly flat.
Mealybugs. Credits: James Castner, University of Florida
Mealybugs
Mealybugs are soft-bodied insects that possess a covering of flocculent, white, waxy filaments. They are about 1/8 inch in length and usually pinkish or yellowish in color. Mealybugs have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental plants. Mealybug damage produces discolored, wilted, and deformed leaves.
Scale and Mealybug Management
- Cultural Control – Plant inspection prior to purchase or installation is the first line of defense against a scale or mealybug population. Make sure to inspect the undersides of leaves and plant stems. Infested sections of plants can be pruned and plant material should be cleaned from the planting area and discarded. Also, you can increase air flow and decrease humidity by proper installation and pruning. Over-fertilizing can also increase pest populations.
Larva of a brown lacewing. Credits: Lyle Buss, University of Florida.
- Biological Control – Predators, such as ladybugs and green lacewings, are usually present in large enough numbers to suppress scales and mealybugs to a desirable threshold. However, broad-spectrum insecticides and bad weather can reduce predator numbers. Look for signs of predation by inspecting dead scales for jagged holes in their waxy coatings. If predation signs are present, use more selective chemical controls and oils as opposed to broad-spectrum products.
- Chemical Control – Timing is everything when it comes to managing scale and mealybug insects. Crawler activity is more pronounced with the flush of new plant growth in the spring. Before application, prune infested plant parts off first to promote greater penetration of insecticides into the foliage. Contact products (acephate, bifenthrin, carbaryl, etc.) must be applied to inhibit the crawler stages of these insects and systemic products (acetamiprid, imidacloprid, thiamethoxam, etc.) can be used on the sessile growth stage. Plants should be sprayed thoroughly to the point of drip or “run off” from leaves, twigs, and stems. Repeated applications may still be necessary even if the timing is right, as crawler populations are often large and crawlers like to hide under old waxy scales. Systemic drenches are also a viable option. With good spray coverage, horticultural oils can kill scales at all stages of growth. Refer to the product label for phytotoxicity and temperature guidelines. Even after successful treatment, the outer coatings of the scales may remain on the plant material for weeks, which can be unsightly. The best way to determine if scales are dead is to squeeze them. They will be dry when squeezed if they are dead and they will ooze liquids if they are living (they were at least alive to the point of being squashed).
For insect identification and additional information on scale control, please see:
A Guide to Scale Insect Identification
UF/IFAS Featured Creatures
Your County Extension Office
