From time to time we get questions from clients who are unsatisfied with the flavor of the fruit from their citrus trees. Usually the complaints are because of dry or fibrous fruit. This is usually due to irregular irrigation and/or excessive rains during fruit development. However, we sometimes get asked about fruit that is too sour. There are three common reasons why fruit may taste more sour than expected: 1) The fruit came from the rootstock portion of the tree; 2) The fruit wasn’t fully mature when picked; or 3) the tree is infected with Huanglongbing (HLB) a.k.a. citrus greening or yellow dragon disease.
Rootstock
The majority of citrus trees are grafted onto a rootstock. Grafting is the practice of conjoining a plant with desirable fruiting characteristics onto a plant with specific disease resistance, stress tolerance (such as cold tolerance), and/or growth characteristics (such as rooting depth characteristics or dwarfing characteristics). Citrus trees are usually true to seed, but the majority of trees available at nurseries and garden centers are grafted onto a completely different citrus species. Some of the commonly available rootstocks produce sweet fruit, but most produce sour or poor tasting fruit. Common citrus rootstocks include: Swingle orange; sour orange; and trifoliate orange. For a comprehensive list of citrus rootstocks, please visit the Florida Citrus Rootstock Selection Guide. A rootstock will still produce viable shoots, which can become dominant leaders on a tree. In the picture below, a sour orange rootstock is producing a portion of the fruit on the left hand side of this tangerine tree. The trunk coming from the sour orange rootstock has many more spines than the tangerine producing trunks.
A tangerine tree on a sour orange rootstock that is producing fruit on the left hand side of the tree. Photo Credit: Matt Lollar, University of Florida/IFAS Extension
Fruit Maturity
Florida grown citrus generally matures from the months of October through May depending on species and variety. Satsumas mature in October and taste best after nighttime temperatures drop into the 50s. Most tangerines are mature in late November and December. Oranges and grapefruit are mature December through April depending on variety. The interesting thing about citrus fruit is that they can be stored on the tree after becoming ripe. So when in doubt, harvest only a few fruit at a time to determine the maturity window for your particular tree. A table with Florida citrus ripeness dates can be found at this Florida Citrus Harvest Calendar.
Citrus Greening
Citrus Greening (HLB) is a plant disease caused by the bacterium Candidatus Liberibacter asiaticus, which is vectored by the Asian citrus psyllid. The disease causes the fruit to be misshapen and discolored. The fruit from infected trees does not ripen properly and rarely sweetens up. A list of publications about citrus greening can be found at the link Citrus Greening (Huanglongbing, HLB).
A graphic of various citrus greening symptoms. Photo Credit: University of Florida/IFAS Extension
Camellia Photo by Kathy Warner UF/IFAS Master Gardener – Nassau County
With their shiny green leaves, compact growth habit and unique blooms, camellias are the winter queen of flowering shrubs. Worldwide, there are about 250 different species of camellias. In the landscapes of Northwest Florida, the most commonly grown species are Camellia sasanqua, Camellia japonica and hybrids of these. Collectors and botanical gardens may have Camellia reticulata, Camellia hiemalis, Camellia vernalis and hybrids of multiple species. The young leaves of another camellia species, Camellia sinensis, are processed for tea, one of the world’s most common beverages. The various species of camellia plants are generally well-adapted to acidic soils, especially those rich in organic material. Camellias requires consistent watering, particularly once the flower buds are set. Most species prefer protection from direct sun during the heat of the day and will bloom well in significantly shaded areas. Individual species and cultivars bloom seasons vary with growing climate. Camellias are classified by their blooming time, ranging from early to late season, relative to other camellias. For extended flowering, plant a variety of cultivars. Early-fall bloomers begin in October and re-bloom through January. Long-bloomers add a few months with flowers from November to April. Camellias that start opening in January and continue through March are referred to as mid-season bloomers. Spring blooming camellias are the last to flower, from March to May. When deciding on particular cultivars also consider the various flower shapes. There are six flower forms, with changes in number of petals and appearance of stamens. Camellias do come with a few potential pest problems. For information refer to: https://gardeningsolutions.ifas.ufl.edu/care/pests-and-diseases/pests/camellia-pests-and-problems.html
COVID 19 has resulted in many cancelled events. But, you may find a local camellia show to see some the fantastic blooms of many different cultivars. Here are a few options:
December 12, 2020 Pensacola Camellia Club, University of West Florida, Conference Center & Ballroom, 11000 University Parkway, Building 22, Pensacola, FL, Skip Vogelsang, (850) 776-7951, lbv3rd@gmail.com
January 10, 2021 Northshore Camellia Club, Southern Hotel, 428 E. Boston St., Covington, LA, Show Chairman: Hunter Charbonnet, hcherbo1@gmail.com, Contact, Judges’ Chair & Show Reporter: James Campbell, rivercamellia@bellsouth.net, (985) 630-9899,
January 16, 2021 Ozone Camellia Club, Slidell Municipal Auditorium, 2056 Second Street, Slidell, LA, Show Chairman: Jim Campbell, rivercamellia@bellsouth.net, Show Contact: Bruce Clement, (985) 259-5527, bwc555@charter.net, Show Reporter: Stella Allen,
January 23, 2021 Camellia Club of Mobile, The Shoppes at Bel Air, 3299 Bel Air mall.,Mobile, AL 36606, Show Chairmen: Walter Creighton & Larry Heard, larry_heard@bellsouth.net, Show Contact: Larry Heard, (251) 661-9392, Judges’ Chair: Jim Smelley, Show Reporter: Jim Dwyer,
Fall is here and Red roselle hibiscus is responding with flowers and fruit. Learn to grow your own Roselle hibiscus and make a delicious tea with UF IFAS Escambia Extension’s Garden to Table segment.
In the Panhandle, fall is the prettiest season for wildflowers. Our roadsides and woodlands are covered with pinks, whites, yellows, blues, purples, and even a little red here and there. Pretty as it may be, the beautiful wildflower look isn’t super appropriate for most yards. It would look unkempt, a little “wild” if you will, would be hard to manage and is probably best enjoyed in natural areas. However, we can bring some of the native colors of fall into our landscapes in a much lower maintenance, refined manner with two Panhandle species that pair excellently together, Muhly Grass (Muhlenbergia capillaris) and Darrow’s Blueberry (Vaccineum darrowii).
Muhly Grass and Darrow’s Blueberry in a local landscape. Photo courtesy of Daniel Leonard.
Muhly Grass, the native grass with the pinkish/purple panicles blooming right now, has gained much popularity in recent years, earning a reputation as a near pest/disease free, drought tolerant, attractive landscape plant. Operating in lieu of more traditional low growing shrubs in landscapes, Muhly is an airy, greenish gray bunch grass growing about 3-4’ tall and wide, lending informal, coastal texture to landscapes most of the year and really shining in fall during its flowering season. Once established, it never needs extra water, prefers little fertilizer, and only needs a rejuvenation prune (or burn – the Leonard preferred method. It’s fun and mimics the role of fire in Muhly’s native ecosystems!) every couple of years to keep it looking tidy.
Unlike Muhly Grass, Darrow’s Blueberry has not caught on broadly in the landscape industry but is no less deserving. This native blueberry species only grows a couple of feet tall, produces edible fruit that wildlife enjoy, and adds an unusual blue green color to landscapes via its tiny-leaved, evergreen foliage. It prefers the same sites as Muhly and is part of the reason they pair so well together. Our mostly sandy, well drained soils work just fine, but both plants can handle soils that are occasionally wet. A bonus, Darrow’s also has tiny, bell shaped flowers in spring that attract all manner of beneficial bee species. This makes it a must in any native pollinator garden!
As good as these species are alone, I think they are better together. In my family’s yard, we created a loose screen of widely spaced (8’ apart) Muhly Grass specimens around a pool, in the spirit of giving the area a “coastal” airy feel, and interspersed Darrow’s Blueberry in between.
The pink Muhly Grass flowers pair nicely with the green blue foliage of Darrow’s Blueberry. Photo courtesy of Daniel Leonard.
The look has been outstanding, particularly in the late summer/early fall. The pinky purple flowers of Muhly Grass complement the green-blue foliage of the blueberries nicely and provide easy, lasting color without having to worry about planting finicky annuals or perennials each season.
Landscaping with natives does not have to look wild and unkempt, nor does it have to be drab and unattractive. Combining native yet showy plants like Darrow’s Blueberry and Muhly Grass makes for an unusual, refined, nearly no-maintenance feature in your landscape. Look for these and other neat native plants at native nurseries and independent garden centers around the Panhandle. If you’d like more information on native grasses, blueberries or any other horticultural topic, please contact your local UF/IFAS County Extension Office! Happy Gardening!
Many people often request a recommendation for a small tree that will be suitable for their landscape and one to consider is the Chinese Pistache, Pistachia chinensis. Although not a native tree, Chinese Pistache does not have invasive potential so it can make a suitable option for both commercial and residential landscapes.
Berries also offer nice fall color. Photo by Beth Bolles, UF IFAS Extension Escambia County
The best features of Chinese Pistache are the fall color it offers with orange leaves, followed by clusters of salmon berries. It will lose its leaves as days shorten but you can enjoy the textured bark during the winter season. Compound leaves offer interest as well during the spring and summer. Adding some medium to fine textured foliage plants under and around trees will provide a nice landscape display.
Chinese Pistache has been an attractive feature in the Escambia County Demonstration Garden for over 20 years. Photo by Beth Bolles, UF IFAS Extension Escambia County
A positive feature of Chinese Pistache is that once it is established, it is tolerant of drought. Expect trees to be about 25 to 30 feet in height with a 20 to 25 foot spread. Each tree will have it own unique branch structure and some pruning will be required when trees are young to develop strong connections. You may plant as a full sun tree to provide a little dappled shade for your garden or use as an understory tree in partial shade.
Normally, you will have one of four answers: “yes”, “no”, “I don’t know” or “what are super bugs?” The answer to the last one is an insect or other pest that has become resistant to chemical treatments through either natural selection (genetics) or an adaptive behavioral trait.
The next question is do you treat insect or pest problems at home with a purchased EPA registered chemical (one purchased from the nursery or other retailer)? If you answered yes, then the next question is how many times in a row do you apply the same chemical? If you only use one chemical until the product is used up, then you might be creating super bugs. Do you ever alternate chemicals and if you answer yes, do you understand chemical Modes of Action (how the pesticide kills the pest)? If you do not, then chances are the rotating chemicals might act in the same way. Thus, you are creating super bugs because in essence you are applying the same chemical with different labels.
Click on image for a larger view. Taken from https://edis.ifas.ufl.edu/in714.
One of the first ways to reduce creating super bugs is to practice Integrated Pest Management (IPM). The very last step of an IPM philosophy is chemical control. You should choose the least toxic (chemical strength is categorized by signal words on the label: caution, warning, and danger) and most selective product. A chemical label advertising it kills many pests is an example of a non-selective chemical. You want to choose a chemical that kills your pest or only a few others. In Extension education, you will always hear the phrase “The label is the law.” To correctly purchase a chemical, you must first correctly identify the pest and secondly the plant you want to treat. If you need help from Extension for either of these, please contact us. Before purchasing the chemical, always read the whole label. You can find the label information online in larger print versus reading the small print on the container.
IRAC phone app.
You now have the correct chemical to treat your pest. Wear the recommended personal protective equipment (PPE) and apply according to directions. If your situation is normal, the problem is not completely solved after one treatment. You might apply a second or third time and yet you still have a pest problem. The diagram explains why you still have pests or more accurately super bugs.
Now the last question is how do we really solve the problem given that chemicals are still the only treatment option? A bit more work will greatly help the situation. You need to download the Insecticide Resistance Action Committee (IRAC) guide and find the active ingredient on your chemical label (http://edis.ifas.ufl.edu/pi121 or https://irac-online.org/modes-of-action/ and select the pdf). If you are like me, you can just download the IRAC MoA smartphone app and type in the active ingredient; otherwise, Appendix 5 in the pdf has a quick reference guide. Either way, you will know the Group and/or Subgroup. A lot of commonly purchased residential chemicals fall within 1A, 1B or 3. The successful treatment option is to select chemicals from different group numbers and use them in rotation. If you start practicing this simple strategy, your treatment should be more successful. Then when someone asks if you are creating super bugs, your answer will be no.
If you have any questions about rotating your chemical Modes of Action, please contact me or your local county Extension agent. For more resources on this topic, please read Managing Insecticide and Miticide Resistance in Florida Landscapes by Dr. Nicole Benda and Dr. Adam Dale (https://edis.ifas.ufl.edu/in714).
