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Be on the Lookout for Crape Myrtle Bark Scale

Be on the Lookout for Crape Myrtle Bark Scale

Being a gardener in Florida is exciting. We have many plants to choose from and the weather is mostly pleasant but always seeming to surprise us. One disadvantage of living in such a place, in addition to having so many growing zones, landscape nurseries, and major shipping ports, is that invasive species that land in Florida don’t like to leave. One newcomer in the lineup of invasive pests is the crape myrtle bark scale (Acanthococcus lagerstroemiae). This invasive insect pest made its way from Texas and, as of a few weeks ago, the only Florida sighting had been in Santa Rosa County. Unfortunately, this pest has now been confirmed in Leon County. Landscapers and gardeners in north Florida should learn how to identify this pest and what options are available for control.

The crape myrtle bark scale, as the name suggests, has a pretty specific host – the crape myrtle (Lagerstroemia spp.). However, in the United States, this scale has also been found feeding on our native beautyberry (Callicarpa americana). Due to the widespread planting of crape myrtles, these should be the gardeners primary focus when looking for this new pest. If present on the tree, it is hard to miss. These scales feed on the bark and are a snow-white color. Being a scale, they produce honeydew that is then covered in black sooty mold. So, if you see a crape myrtle with black branches, look closely and you may see the white scales. If you crush these scales and they leave a pink goo on your fingers, then you very likely have crape myrtle bark scale. Of course, you can send a picture or sample to your local county extension office for confirmation.

Black sooty mold and white scales along the trunk and branches are a tell-tale sign of crape myrtle bark scale. Credit: Mark Tancig, UF/IFAS.

If you do happen to find crape myrtle bark scale in your own landscape, or one that you manage, proper control is important to prevent it from moving along any further. Since scales suck on sap and are protected by an outer shell, systemic insecticides are the preferred product for effective control. These include the neonicotinoids, such as imidacloprid (Merit) and dinotefuran (Safari). The larval stage can be controlled with a horticultural oil, sometimes mixed with another insecticide like bifenthrin (Talstar), however, this will not control the adults. Another option is to completely remove the tree and burn all of the plant material.

Excessive sooty mold has turned these branches black. Be on the lookout for crape myrtles looking like this to help identify crape myrtle bark scale. Credit: Jim Robbins, Univ. of Ark. CES. Retrieved from bugwood.

The crape myrtle bark scale can significantly reduce the aesthetic value of crape myrtles due to the black sooty mold that covers the bark. It is also known to reduce flowering and can lead to thinning of leaves. Since crape myrtles make up a big part of our managed landscapes, let’s all work together to scout for this pest and control it when found. If you have questions, please contact your local county extension office.

Difference in flowering due to crape myrtle bark scale damage. Credit: Jim Robbins, Univ. of Ark. CES. Retrieved from bugwood.

For more information, please see this UF/IFAS document and this Clemson website for more photos and control information.

How Weather Affects Citrus and Other Dooryard Fruit Varieties

How Weather Affects Citrus and Other Dooryard Fruit Varieties

The weather is the most important factor determining where certain fruits can be successfully grown. Terms such as chilling requirement and cold hardiness play a major role in both species and variety selection.

Most fruits which grow in the Panhandle are deciduous, meaning that during the winter, they lose their leaves and go through a semi to full dormancy period. This period is a much needed rest and reset for the plant. The cool season actually helps the plant to rebound for another fruiting season and affects how well the plant will yield fruit. This is where the term “chilling hours” comes into play.

Temperatures below 45 degrees Fahrenheit are considered “chilling”.  The number of hours below 45 degrees accumulated throughout the winter determines the total amount of chilling hours. Different species of citrus and dooryard fruit, along with different cultivars of these plants differ in the amount of chilling hours need for that all important rest & reset period. Satsuma is a popular fruit trees in our area, as it is by far the most cold hardy citrus. Evidence suggests that the satsuma can survive a temperature as low as 14 degrees Fahrenheit.

Figure 1. Mature satsumas ready for harvest.

Credit. Pete Anderson. UF/IFAS Extension.

What happens if the plant doesn’t receive the needed amount of chilling hours? Plant hormones can be disrupted, and both leafing and blooming could be light and come outside of the normal range of the season. So, where do we stand in the Panhandle for overall chilling hours? Typically, we see approximately 500 hours chilling hours. Therefore, its best to plant citrus and dooryard fruit that have the characteristic of needing 500 or less hours for chilling. Please see this informative document on citrus and dooryard fruit varieties: https://edis.ifas.ufl.edu/publication/MG248

Now, on to the term cold hardiness. By definition, this is the plants ability to withstand cool season temperatures without injury. Most tropical fruits cannot tolerate our Panhandle temperatures. Those of us that cut back banana trees every year know this all too well. To check your plant hardiness zone, please see the USDA Plant Hardiness Zone Map: https://planthardiness.ars.usda.gov/

Before you plant a fruit tree, make sure you understand about its cold hardiness and whether or not it has a chilling requirement. This will both save you money and a headache, in the end. If you’re in doubt about a particular variety, contact your local extension office.

Information for this article can be found at the UF/IFAS EDIS Publications, “Dooryard Fruit Varieties: https://edis.ifas.ufl.edu/publication/MG248 & “The Satsuma Mandarin”: https://edis.ifas.ufl.edu/publication/CH116

UF/IFAS Extension is an Equal Opportunity Institution.

Understanding Chill Hours

Understanding Chill Hours

Any North Florida resident who has tried their hand at growing apples, peaches, or plums may occasionally find themselves frustrated by a year (or two…or three) with a poor or nonexistent harvest. What has gone wrong? Are the trees getting a disease? Were they not fertilized properly?

It may be that the tree owner has done everything correctly, but the weather is actually to blame. The answer to “what has gone wrong?” may lie with a concept called “chill hours”. Plants that are adapted to living in colder climates need some way to figure out when the winter is over. If a plant starts blooming too early, it’s likely that a frost will come along and knock out this year’s flowers. No flowers, no fruit. For a plant, this means no little baby plants this year to keep the species going. To avoid this, some plants have figured out a way to detect and keep track of how cold it’s been in a particular year. When enough hours of cold weather have accumulated, that’s usually a safe signal that spring must be near. This means it’s time to blossom when the weather next warms up.

Usually. Different varieties of plants are adapted to blossom at different times of year, depending on the average amount of cold weather the area they live in gets each year. A plant from a colder climate might not start growing flowers until it has detected 1,000 hours of cold…or more! Given that the temperature range that counts as a chill hour is around 32-45 degrees Fahrenheit, you might correctly guess that such varieties will NOT do well in Florida. In north Florida, we receive somewhere from 500-700 chill hours each year. This winter (as of February, 2023), we have received 479 chill hours in Walton County.

Chill hour total for Walton County, as of Feb 1, 2023

That’s not a lot, and we may not get much more weather that plants recognize as cold enough to count. Apple growers with varieties that need even as few as 500 chill hours may not be making many pies this year. So what can be done?

First, temper your expectations. Understand that even though we may get the occasional hard freeze, it may not count any more toward the chill hour requirement than temperatures just above freezing. Then, when it warms up the following week, those 70 degree temperatures may actually set BACK the chill hour clock for some plants.

Second, choose varieties that require few chill hours in the first place. A ‘Honeycrisp’ apple, needing 800-1000 chill hours each year, is probably never going to produce fruit in the panhandle of Florida. Other apple varieties might, though! Try varieties such as ‘Anna’ (which needs only 300 chill hours), ‘Dorsett Golden’ (250 hours), or ‘Tropic Sweet’ (300 hours). For peaches, try varieties like ‘GulfAtlas’, ‘Gulfcrimson’, or ‘Gulfsnow’ (400 hours each).

Third, consider learning to love other types of fresh fruit. Persimmons, figs, kumquats, and loquats may not show up very often in treasured family recipes, but they can offer a tasty alternative to plants that simply might not be well adapted to our climate.

Peaches are popular, but they may not produce fruit every year!

For more information, try these links:

To calculate how many chill hours your specific area has received, check out the tool at agroclimate.org.

For information on apples, peaches, plums, blueberries, or other fruits, try our EDIS publications on each.

You can also, of course, contact your local Extension office for help as well!

Evan Anderson

Walton County Horticulture Agent

Guidelines for Hiring a Landscape Professional

Guidelines for Hiring a Landscape Professional

Garden and landscape maintenance can be relaxing, but it can also be stressful. Sometimes you may just not have the time or the patience to get all the work done. In that case, you may choose to hire a professional to get your yard to looks its best. A number of things should be considered when selecting a company. First of all, make sure you find a company that provides the services needed. You probably don’t want to hire a business that specializes in planting food plots if you need some trees removed from around your house. And you may not want to hire a company that manages sports fields if you want some trees and shrubs installed. Please find a checklist below of some things to consider when choosing a landscape professional.

Applying the proper amount of fertilizer keeps your landscape healthier and protects local waterbodies. Credit: UF/IFAS.

Insurance, Licenses, and Certifications – Make sure to hire professionals who meet all state and local license and insurance requirements for the work they are are contracted for.

  • General Liability Insurance – General liability insurance protects against bodily injury, property damage, and personal injury. Ask for proof of this coverage.
  • Workers’ Compensation Insurance – Worker’s compensation insurance provides medical and wage benefits to employees who are injured or get sick at work. More information on this coverage can be found at myfloridacfo.com.
  • Pesticide Applicator License – A pesticide applicator license is required for individuals spraying pesticides in and around your home. Some licenses allow the applicator to spray your entire landscape while others only grant the applicator to lawfully spray ornamental beds and shrubs around the home. You can search for applicators by name or license number at Licensed Pesticide Applicator Search.
  • Fertilizer Applicator License – A fertilizer applicator license is required for individuals applying fertilizer to turf and ornamentals on your property. You can search for applicators by name or license number at Licensed Pesticide Applicator Search.
  • FNGLA – The Florida Nursery, Growers and Landscape Association (FNGLA) certifies landscape professionals on their landscape installation and/or maintenance expertise. You can search for certified individuals at FNGLA Certifications.
  • FFL – The Florida-Friendly Landscaping Program offers a Florida-Friendly Landscaping Certified Professional (FFLCP) certification to individuals are familiar with the latest UF/IFAS recommendations and who implement the 9 Florida-Friendly Landscaping principles by using environmentally friendly landscape management practices. A list of certified individuals can be found at Florida-Friendly Landscaping Certified Professionals Listing.
  • ISA – The International Society of Arboriculture certifies landscape professionals and arborists on their expertise on tree care and installation. You can search for certified arborists at Certified Arborist Search.

In addition to checking for accreditations, a number of questions can be asked to determine if a company meets your needs. These questions will help determine whether the company follows environmentally friendly landscape management and installation practices.

  • Does the landscape professional understand irrigation system design and know how to calibrate an irrigation system?
  • Does the landscape professional maintain mowing and pruning equipment and tools to make clean cuts?
  • Does the landscape professional maintain turf at the appropriate height for the species/cultivar being grown?
  • Does the landscape professional follow UF/IFAS fertilizer recommendations for fertilizer rates and products?
  • Does the landscape professional apply fertilizer only when turf and ornamentals are actively growing?
  • Does the landscape professional use soil tests to help determine fertilizer needs?
  • Does the landscape professional regularly check turf and ornamentals for insect pests and diseases?
  • Does the landscape professional follow recommendations for plant installation and spacing?

These are just a few things to consider when hiring a landscape professional/company. After reviewing qualifications and asking tough questions you’ll also want to consider cost. Make sure to consider the scope of work of the companies that gave you quotes. For more comprehensive guidelines, please check out the UF/IFAS Publication Guidelines for Hiring a Florida-Friendly Landscape Professional.

Educational Opportunity: Fruit and Vegetable Meeting

Educational Opportunity: Fruit and Vegetable Meeting

Would you like to make money off your land?  Are you looking to diversify your current plans on your property?  Jackson County is hosting a fruit and vegetable meeting on January 26, 2023, and this just may be the perfect way to start off your new year! 

Squash vine borer larvae can most easily navigate the stems of summer squash varieties. Photo by Molly Jameson.
Photo by Molly Jameson.

When thinking about what it means to be successful in planting your garden or having fruit trees, often the first thing that comes to mind is a healthy quality crop.  This starts with the health of your soil.  We will have two specialists that cover soil health and the benefit of adding cover crops to your rotation during the off season.  The second thing that might come to mind when wanting to be successful is how to start? how much time do I have to devote to gardening? and how much do I want to do? This meeting will also have a specialist coming to Marianna to cover how to get started on a property with a specialty crop.  Even though this information may be geared towards new farmers, it could also be very useful to new land owners and community residents just wanting to do more on their property.  You may find that you have so much extra produce that you want to have a little fruit stand!

There will also be a session on the importance of drip irrigation, fertigation and how to implement these practices. Drip irrigation will not only save you money in the long run with the use of less water, but it is also much better for overall plant health by reducing pest and disease problems.   Fertigation is the process of adding soil amendments, water amendments and other water-soluble products into an irrigation system.  This process can be both beneficial to the plants and cut back on the time it would take to fertilize by hand.

The next session on specialty vegetable and fruit crops will teach about the various exciting specialty crop opportunities in the Tri-State area such as artichokes, blackberries, Seminole pumpkins, and more.  Finally, the meeting will also cover cucurbit disease updates and will be extremely useful if you already have a field or garden of watermelons, cucumbers, or squash! Come with questions!  CEUs will be offered as well if you are a homeowner that holds a pesticide license.  

Organic matter is the “glue” that will hold your soil together. Photo by John Edwards.

While, the audience for this conference is primarily small to medium sized, diversified cucurbit and vegetable producers in the tri-state region including the counties in the Panhandle, Alabama, and Georgia, the residential community is welcome to attend and will truly benefit with learning about soil health, cover crops, fertigation, drip irrigation, and specialty crops. The conference will be held at the Jackson County Extension Office in the Peanut Hall.  We are planning a full morning with educational sessions and lunch to follow. 

This meeting will be $5 at the door and pre-registration is highly encouraged.  Please call our office at 850-482-9620 to reserve your seat and if you have any questions.

Tri-State Fruit and Vegetable Meeting

Thursday, January 26, 2023, 8:00 am- 1:00 pm at the Jackson County Agriculture Offices Auditorium, 2741 Penn Ave., Marianna.