Fragrant Summer Landscape Tradition
Fig. 1 Magnolia flowerA southern landscape tradition, Magnolia grandiflora is an American native tree. Southern magnolia is a large upright spreading tree that creates dense shade and can attain a height of eighty feet. This slow growing evergreen tree flowers even when young and prefers a moist, rich soil that is well drained, a perfect tree for irrigated landscapes. Use mulch to encourage additional moisture in our sandy South Florida soils. This tree is especially beautiful in late spring and early summer when it bears it’s large, dinner plate size, fragrant creamy-white flowers. It’s four inch long subsequent cone-like fruit contains red seeds that birds enjoy. You may select available cultivars of magnolias for your garden to ensure your desired shape and density. For information on our native flowering trees call the Palm Beach County Cooperative Extension Service Master Gardener volunteer hotline at 233-1750.
Figure 2 magnolia fruit/seed
New Whitefly Threat in Palm Beach County
Photo credit UF Osborne
The silverleaf whitefly Q-Biotype is now here in Palm Beach County.
In May 2016, for the first time the pesticide resistant silverleaf whitefly (Bemisia tabaci) Q-Biotype has been found established in Florida (Palm Beach County) landscapes. Another genetically different whitefly that looks exactly the same, called the B-Biotype came into Florida around 1996 and created havoc for nursery poinsettia and commercial vegetable production by displacing the original “A-Biotype.” Since then, the neonicotinoid insecticides helped manage it and other whiteflies.
The Q-Biotype (we will just call it Q whitefly for the remainder of this document) developed in the Mediterranean region of Europe likely due to their intensive form of vegetable production. All of the biotypes of silverleaf whitefly look exactly alike. They can only be differentiated by genetic testing – and sometimes by their sensitivity to, or tolerance of certain insecticides. The genetic tools were not available in the mid-1990’s to reduce the confusion about the taxonomy of these insects back then. Old names like sweetpotato whitefly and Bemisia argentifolii can still be found in documents available on the web.
As of June 1, 2016, the Q whitefly has been positively identified in landscapes in Palm Beach Gardens, Palm Beach, Boca Raton and western Boynton Beach. That is a broad area and implies that the Q whitefly is probably more widespread throughout the county – although, we will have to wait and see on that. Interestingly, only B-Biotypes have been found so far in Broward and Monroe Counties, although they are also experiencing unusually high silverleaf whitefly control problems in spots. Also of note is that Q whitefly transmitted viruses have been devastating vegetable production in some areas of the world. Silverleaf whitefly has greater than 900 known host plants and can transmit more than 100 plant viruses. So far, locally we have seen the Q whiteflies mostly on hibiscus and crossandra in landscapes. The whitefly transmits at least two common tomato viruses in Florida, and one common pepper virus. In fact, if you grow garden tomatoes in Palm Beach County, you probably have had tomato yellow leaf curl virus transmitted the B-Biotype on them in the past. Viruses cannot be treated in vegetables, and must be controlled by managing the insects and destroying the plants. Thankfully, we are at the end of tomato and pepper commercial production for this season, but you can see the implications for next season if limited effective insecticides are available for this difficult to manage pest.
Recommendations for landscape management are being developed and evolving. Residents can use repeat applications of insecticidal soaps or oils to obtain some control. Be sure to completely cover all leaf surfaces and avoid spraying during the hot parts of the day. If you are using other common insecticides and still not getting control, feel free to contact our Master Gardener Hotline during normal business hours, Monday through Friday excluding holidays at 561.233.1750 or email email@example.com The Master Gardeners can also help you identify if you actually have silverleaf whitefly, or some other insect.
Websites for Additional Information
Palm Beach Whitefly Task Force: http://www.pbcgov.com/coextension/horticulture/whitefly
How to Send a Sample if You Suspect Q Whiteflies: http://www.pbcgov.com/coextension/horticulture/whitefly/pdf/Publication%206.pdf
How to Tell if You Have Bemisia Whiteflies: http://www.pbcgov.com/coextension/horticulture/whitefly/pdf/Publication%203%20-%20final%20version.pdf
Tropical Fruits Make Summer Sweet
Fig. 1 Carambola fruitTropical Fruit can be a great addition to your diet and if home grown can assist with family food expenses. Tropical fruit can be grown in your own back yard. Choosing tropical fruit that produce in May and June include rose apple, banana, carambola, fig, guava, jackfruit, lychee, mango, papaya, passion fruit and pineapple. Choosing the right fruit tree, shrub or vine is dependent upon where in your home yard they will be growing. Characteristics of your yard as how much sun, shade, moisture you have will determine which tropical fruits will do best. Getting the best variety of the tropical fruits available is important, being sure to choose an improved variety that has been properly grown. For information on tropical fruits recommended for South Florida, see University of Florida publication ‘Dooryard Fruit Varieties’
https://edis.ifas.ufl.edu/mg248 or call the Palm Beach County Cooperative Extension Master Gardener Volunteer hotline 233-1750.
Pepper Variety Evaluation
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Trimming Your Hedges
Fig 1 Blue color form Native Palmetto Trimming hedges properly is key to beautiful, full and healthy long-lived shrubs. The University of Florida recommends trimming shrubs while the new green growth is emerging. The most common mistake people make when trimming a hedge is cutting the shrub into a sharply-edged box shape. It's important to trim a hedge so that the top is narrower than the bottom; this way, sunlight can reach all the plant's leaves. The bottom branches of "box-shaped" hedges usually thin out—and even die—from lack of sunlight. Hedges that have been improperly trimmed become top heavy with green growth, and leafless at their base which require rejuvenation pruning or replacement. Rejuvenate your shrubs by removing one-third of the plants old stems to the ground each year for three years. For information on pruning to rejuvenate, call the Palm Beach County Cooperative Extension Service Master Gardener Volunteer Hotline at 233-1750 M-F 9-4
Zika Mosquito-Transmitted Virus
The Zika virus is a mosquito-transmitted disease that is causing concern in Florida and around the world. Click below for frequently asked questions, risks of the virus, how to avoid it, and other information.
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Chalice Vine in Flower Mounts Botanical
Garden parking lot 1/25/2016My mother-in-law had a mantra, ‘take time to smell the roses’. It is a good thing, to be able to walk out into your backyard and smell fragrant flowers. Zone 10 most fragrant plants are unforgettable if you have them growing in and around your yard. I have enjoyed the scent of my neighbor’s night blooming jessamine(Cestrum nocturnum) and I personally grow the night blooming ‘Lady of the Night’(Brunsfelsia nitida). These night blooming shrubs bloom mostly spring and summer. The interesting variegated chalice vine(Solandra longflora) has a coconut-like fragrance to its 10 inch yellow flowers which begin to flower in late fall. Frangrant during the day include our native Fiddlewood(Citharezylum fruiticosum) which produce very fragrant white flowers from spring through fall. Many cultivars of gardenias(Gardenia jasminoides) exist which offer considerable variation in plant size, flower form, and blooming time and duration. Popular gardenias include ‘Miami Supreme’, ‘Belmont’, ‘Frostproof’, ‘August Beauty’, and ‘Radicans’ These grafted gardenias are usually more vigorous and produce more and larger flowers than gardenia shrubs that are not grafted. For information on fragrant plants for your garden call the Palm Beach County Cooperative Extension Service Master Gardener Volunteer Hotline 233-1750 M-F 9-4.
“New! 2016 Worker Protection Standard (WPS) Revisions Information Web Page”
The Worker Protection Standard (WPS) applies to farm, forest, nursery and, greenhouse operations that produce agricultural plants. Revisions to the WPS, made by the United States Environmental Protection Agency (EPA), were signed into law in 2016. Farm, forest, nursery, and greenhouse operations must comply with most of these revisions beginning January 2, 2017.
New! Sugar Cane Mosaic Virus on Floratam St. Augustinegrass
Learn more about this serious new disease killing Floratam St. Augustinegrass lawns.
Palm Pruning Caution
Canary Island Date Palm
University of Florida research scientists are advising our landscape maintenance community to sterilize their pruning tools before and after they trim their Canary Island Date Palms-Phoenix canariensis to avoid spreading a deadly disease.
Dr. Monica Elliott, a plant pathology professor, published a study recently in the APS Journal of Plant Disease, June 2015 demonstrating that Fusarium oxysporum f. sp. canariensis, a pathogen that spreads fusarium wilt of Canary Island Date Palm, was discovered on a wild or Senegal date palm in Palm Beach County.
Some diseases, such as fusarium wilt of Canary Island date palm (http://edis.ifas.ufl.edu/pp139), are known to be spread by pruning with infested tools. Tools used to prune infected palms will be covered with a residue containing fungal material. If this tool is then used to prune living leaves on a healthy palm, the fungus will be transferred in the process. When pruning these palms, tools should be soaked in a disinfectant solution for 5 minutes before using them on another palm. This is also a good reason not to prune off living older leaves to achieve the so-called "pineapple" effect on Canary Island date palms. Freshly cut living leaf bases release volatile chemicals that attract palm weevils, a serious insect pest of this palm (http://edis.ifas.ufl.edu/IN139). Removing completely dead leaves and flower and fruit stalks from palms is never a problem.
Common products used to disinfect horticultural tools and surfaces:
Fumes can be harmful
Short life span of bleach solution (about ½ effect is gone after 2 hours), requires fresh batches immediately before disinfecting tools
10% bleach solution (1 part bleach : 9 parts water)
Rinse with water after soak
Grocery and hardware stores and home-improvement centers
(Ethanol or Isopropyl Alcohol)
Immediately effective (no soaking)
Can be used as wipe
No need to rinse
Wipe or dip tool in 70 - 100% alcohol
Grocery stores and pharmacies
If you have a palm exhibiting problems call the Palm Beach County Cooperative Extension Master Gardener hotline at 233-1750 M-F 9-4, or stop by the office 531 North Military Trail West Palm Beach with your palm frond sample.
You may have noticed large numbers of millipedes seemingly invading homes and businesses this year. During this particular time of year the Palm Beach County Extension office receives many complaints about millipedes. Download the fact sheet to learn more about millipedes.
The Cattle Identification Rule (Chapter 5C-31, Florida Administrative Code) has been published with an effective date of September 4, 2014. This rule is intended to improve our ability to respond to serious disease outbreaks and to help the industry maintain out-of-state markets.
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