by Matthew Orwat | Jan 13, 2016
Crapemyrtle Scale, UF / IFAS Extension
During cold January weather, one doesn’t often think about spraying fruit trees and ornamental shrubs for spring insects and diseases. It’s just not on the radar. The fact is January and February are the best time to apply dormant sprays to combat insect and disease issues. Many ask, “What are dormant sprays” ?
Dormant sprays act on insects or disease pathogens differently. Many insects overwinter on trees and shrubs, either as eggs or immobilized in a protective shell (scale insects). Horticultural oils applied during cool dormant conditions work by smothering the eggs of some insect species or encapsulated scale insects. Since they cannot breathe, they die.
On the other hand, dormant sprays containing copper or sulfur actually kill latent fungal spores that are ready to infect the moment weather warms. They also burn tender young plant tissue, so can only be used when the plant is not actively growing. These preventative sprays can delay disease incidence in early spring and allow for reduction or elimination of regular fungicide applications. The old adage “an ounce of prevention is worth a pound of cure” surely applies to these situations.
There are several products on the market for dormant applications.
Dormant oil is a type of horticultural oil, made of refined petroleum products, for application on trees or shrubs when the trees are not actively growing. It has been in use for over 100 years. They are effective in the suppression of scale insects and mites. Care must be used to not apply them when daytime temperatures are above 75 degrees or night temperatures below 28 degrees. Other horticultural oils exist that can be applied during the growing season to control soft-bodied insects, but not during extremely hot weather. Many different brands exist, some are certified organic by OMRI. They can be purchased at most garden centers, but the best selection is usually found at your independent nursery or farm store.
Cottony Cushion Scale, Image Credit, Matthew Orwat, UF / IFAS Extension
Dormant fungicides can be classified into two groups. Those that contain copper and those that contain sulfur. The most common preventative remedy for fungal disease is lime-sulfur. It is applied to dormant plants and actually sanitizes the stem, killing all fungal spores. It cannot be used during the growing season since it burns leafy tissue. Caution must be taken when mixing and loading since, being an acidic product, can burn the skin. Wear chemical resistant gloves when applying (bought at your local hardware store for $4.00-$10.00), safety goggles and follow all label directions carefully. Also, never apply lime-sulfur within one month of horticultural oil applications. It should be applied in early to mid February, avoiding hard freezes for the 24 hours around application time.
Dormant copper sprays are effective on both bacterial and fungal pathogens and used primarily on fruit crops for the suppression of many fruit diseases including fire blight, bacterial leaf spot, powdery mildew, downey mildew and anthracnose. One popular option, the “Bordeaux Mixture” blends copper with lime. This lime reduces the acidic nature of the copper, thus reducing tissue damage when applied to plants. Always read the label for proper personal protective equipment and dosage rates, to avoid copper toxicity.
For more information, contact your local extension agent or consult these extension publications from: Disease Management Strategies, and Pest Control Using Horticultural Oils .
by Beth Bolles | Dec 30, 2015
Information on gardening practices is freely shared between gardeners and many times the good advice is helpful in plant selection and improving plant growth. There are some passed along practices that are not always suitable for every situation and gardeners may need to investigate a little deeper before implementing the good advice.
Soil test kit available form your local Extension office. Photo: Mary Derrick, UF/IFAS.
One common recommendation from gardeners is to apply Epsom salts to the soil to improve plant growth. Gardeners may have used Epsom salts for various plants in the garden and viewed plants that appear to grow better or have improved leaf color. Therefore a general recommendation to help others who have some general plant problems or off color leaves is to apply Epsom salts.
Before you apply Epsom salts to your garden, understand that it is an inorganic fertilizer, specifically magnesium sulfate. Plants make their own food but they derive most of their nutrients needed for important functions form the soil. Magnesium is one of the nutrients that is essential in photosynthesis. At times, our sandy soils may be lacking in nutrients but there may be plenty of nutrients available for plants.
The recommendation to apply Epsom salts may sound like a good idea but gardeners should always make sure that magnesium is needed before any applications. Too much magnesium in the soil can interfere with the uptake of other nutrients by plants. You could create more of a problem by indiscriminately applying Epsom salts when magnesium is not needed.
As you hear often from the University of Florida Extension, conduct a soil test before applying fertilizer to determine the major nutrient levels available in your soil. This $7.00 test will help you better manage plant nutrition. If you need assistance interpreting soil test results, contact your local county Extension office.
by Beth Bolles | Dec 4, 2015
A visit to a nursery and homeowners will see so many new selections of plants for the landscape. Some of these plants are new plant developments and may include plants we could not previously grow in Florida’s heat and humidity. One new plant series is the Southgate® Rhododendrons.
Anyone from more northern areas of the South is very familiar with the rhododendrons that offer showy spring blooms. Those particular rhododendrons just don’t make it in our Florida climate.
The Southgate® series from Louisiana were developed to be more tolerant of our weather conditions. Homeowners must still consider plant placement very carefully since these plants have some specific requirements even in Florida. Plants will do best in shade or filtered shade, especially in the afternoon. They do like an acid soil amended with compost and areas that are well drained. Homeowners will need to supply water during the growing season to maintain a uniform soil moisture.
Rhododendron foliage with buds.
Consider trying one of these newer rhodendrons if your landscape has a suitable spot and you will definitely enjoy a bright spot of color come spring.
Special Note: If you have animals or children be cautious since all plant parts are toxic if ingested.
by Mary Salinas | Dec 4, 2015
The cooler weather in the wintertime makes it a great time to plant trees and shrubs. That is why Arbor Day in Florida is the third Friday in January. In 2016, that event is January 15.
Baldcypress growing at the edge of a pond. Photo: Julie McConnell, UF/IFAS
Start your planning now with doing a site assessment on your landscape, then choosing the right trees and shrubs for your particular environmental conditions.
Here are some great sites that offer online tools for finding just the right species:
Florida Tree Selector
The Florida-friendly Guide to Plant Selection & Landscape Design
Florida Native Plant Society Locator
And if you want to find out just how much your established trees are worth, use this National Tree Benefit Calculator!
For more information:
Planting Trees in the Landscape
Arbor Day Foundation: Florida
by Matt Lollar | Nov 18, 2015
Yaupon hollies (Ilex vomitoria) are evergreen, provide great fall/winter color, and can adapt to numerous landscape situations. They are also very durable and can survive extreme drought.
Characteristics
Yaupon hollies are dioecious, meaning male and female flowers are produced on separate plants and berries are only produced on female plants. Flowers are creamy white, but not showy on both male and female plants and berries can range in color from red to yellow depending on cultivar. The plants are favored by wildlife – pollinators are attracted to the flowers and birds love the berries.
Yaupon hollies are native plants with a number of different cultivars available at plant nurseries. ‘Jewel’ is a cultivar that produces an ubundance of red berries and ‘Aureo’ produces yellow berries. ‘Nana’, a dwarf, compact male cultivar is an excellent replacement for boxwoods. Large growing cultivars can grow to 15 to 25 feet tall and can be shaped as trees or left as large shrubs. ‘Folsom’s Weeping’ and ‘Pendula’ are two weeping cultivars that can be utilized as dramatic specimen trees.
Dwarf Yaupon hollies will naturally form a mound without pruning.
Credit: Beth Bolles, UF IFAS Extension Escambia County
Yaupon holly fruit and foliage. Photo courtesy UF/IFAS.
Plant Care
Yaupon hollies prefer to be planted in full to partial sun. It is important to note that they are drought tolerant and require a site with well-drained soil. Because only the female plants produce berries, it is best to purchase plant material when plants contain berries in late fall and winter. Yaupon hollies spread readily by vegetative sprouts. Sprouts should be pruned down to the soil line 2 – 3 times per year. They do not have many disease or insect problems, but scale, leaf miners, mites, and aphids can sometimes be a problem.
Fun Facts
The leaves of the yaupon holly contain a higher caffeine content than any other plant native to North America. The Seminole Indians would purposely brew a concentrated “Black Drink” tea to induce vomiting and diarrhea for believed purification. Southerners utilized the caffeine in the leaves during the Civil War. If the leaves are steeped for a short period, a black tea or coffee substitute can brewed. A related species of holly (Ilex paraguariensis) from Brazil is used to make a drink called Yerba Mate, which is as popular in South America as coffee is in North America.
For more information on yaupon hollies, please visit the publication located at this link https://edis.ifas.ufl.edu/st311.
by Matthew Orwat | Nov 5, 2015
Waxmyrtle. Image Credit UF / IFAS Solutions
Myrica cerifera Southern Waxmyrtle, Bayberry is a large shrub to small tree that is now native to much of Florida and much of the Southeastern United States. It was introduced to Europeans in the 1700s and is considered native by many botanical authorities. Sources disagree to the validity of its native status. It is usually found as an understory plant in lightly forested areas, swamps, brackish areas, as well as around old home sites.
It was planted widely in the 18th,19th and early 20th century as a plant for medicinal and industrial purposes. Four pounds of its berries will yield one pound of wax for candle making. When processed, this wax was also used in surgeon’s soap, shaving lather, and sealing wax. Fermented leaves were used to produce a substance which was said to treat fever, stomach aches, and headaches.
Southern Waxmyrtle can reach up to 25 feet but is best maintained as a 10-20 foot multi-trunked shrub or small tree. It can also be trained as a smaller hedge and several dwarf form exist. Landscapes are enhanced by the shrubs’ olive green foliage, leaf aroma, open, rounded form and waxy blue-green berries. Wildlife enjoy the berries as a food source as well. They can provide dappled shade for outdoor entertainment spaces or front entrances.
Waxmyrtle Leaves. Image Credit Brent Sellers – UF / IFAS Extension
Another benefit of Waxmyrtle is that it can be used in tough-to-landscape roadside and coastal areas since it is both pollution and salt tolerant and will cease to require irrigation once it is established. ‘Pumila’ is a dwarf cultivar suitable to small spaces.
Waxmyrtle is susceptible to few pests and diseases but can occasionally be attacked by webworms, mites and caterpillars. These can be controlled by pruning out of infested areas, forceful applications of water or Bt (Bacillus thuringiensis for caterpillar). It is also occasionally susceptible to canker on old branches and Fusarium wilt in central and south Florida. It is also considered a weed in pasture situations.
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