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 Gary Knox | Apr 20, 2016
The huge flowers and leaves of Ashe magnolia make it one of my favorite native flowering trees. Individual flowers may be 6 – 12 inches in diameter and are white with purple blotches at the bases of the 3 inner petal-like tepals. When in flower, as they are now in April, the huge white blooms are impossible to miss because of their size and color.
Ashe magnolia. Photo credit: Gary Knox, UF/IFAS.
The leaves are similarly huge, growing 1 – 2 feet long and up to 1 foot across. These large, banana-like leaves offer interest and coarse texture to any landscape.
Ashe magnolia grows as a small tree with a loose, open branching habit up to a height of about 25 feet. The large, light green leaves have whitish undersides and emerge in mid spring prior to flowering. Leaves turn yellowish and fall in autumn, usually without any dramatic color change. Pollinated flowers are followed by reddish, cylindrical, 3-inch fruits producing bright red fleshy seeds in early August.
Native to the Panhandle. This small tree is relatively unknown because of its rarity. Ashe magnolia, Magnolia macrophylla var. ashei, is native in only a few counties in the Florida panhandle and is endangered because of this limited distribution. It is primarily found on the slopes of ravines, growing in the understory of mixed hardwood forest. While it is now illegal to remove this plant or its seeds from the wild, nurseries can grow this plant using seeds from long-cultivated landscape trees.
Garden cultivation. Ashe magnolia makes a lovely small flowering tree if planted in the right location. It grows best in rich, well-drained soil under partial shade, although full sun is tolerated if plants are irrigated during drought. Sheltered sites are best since strong winds can shred the papery leaves and break the brittle branches. You won’t have to wait long for this plant to flower; a unique aspect of Ashe magnolia is that it flowers when young, reportedly when as small as 1 foot tall! Another unusual characteristic is that this Florida native plant is hardy north into USDA plant hardiness zone 6.
Given this species’ beauty, rarity and nativity to the Panhandle, I think it is almost an obligation for panhandle Floridians to cultivate and showcase this plant in our gardens while preserving it in our forests! Seek out specialty nurseries to obtain one of these rare beauties for your garden.
For more information:
Atlas of Florida Plants: Ashe Magnolia
Ashe Magnolia at the United States Botanic Garden
USDA Ashe Magnolia Plant Profile
by Carrie Stevenson | Mar 2, 2016
Even large, healthy oaks may fall during a tornado. Photo credit: northescambia.com
When we think of bad weather in Florida, hurricanes are typically the first thing that comes to mind. In reality, Florida is 4th in the nation in tornado frequency—and when adjusted for frequency per square mile, we are actually number 1. Residents of Escambia County are believers now, as the community reels from enduring two tornadoes in the span of a week. Both rated as EF3 storms, the winds in the twisters (136-165 mph) were nearly equivalent to a Category 4 or 5 hurricane. The western Panhandle and much of south Alabama were under tornado watches as the most recent band of thunderstorms moved through.
Based on a thorough study of surviving trees after hurricanes in Florida, there are several species of trees best suited to windstorms. For north Florida, some of the top species are: Florida scrub hickory, several native holly species, Southern magnolia, sand live oak, myrtle oak, and bald and pond cypress. Data from the full study and an in-depth overview is available from the University of Florida. To prepare for a heavy thunderstorm or a milder hurricane, it is wise to replace or plant trees with the most wind-resistant species. Because of the damage from falling trees in storms, many homeowners are nervous about planting trees. However, there are so many benefits to healthy trees in a landscape that they vastly outweigh the small risk of them falling.
Keep in mind that tornadoes are the most violent natural disasters and may cause complete devastation of homes, neighborhoods, and forests in a matter of seconds. After the Escambia County tornadoes, we witnessed large uprooted trees, downed power lines, flipped vehicles and blown-off roofs. Several homes and apartments were completely flattened or blown off their foundations. Luckily, the odds are in one’s favor of not getting hit directly by a tornado—because there’s often little anyone can do for a landscape in that situation. It’s best to hunker down in a windowless inner room or hallway, which saved the lives of hundreds during the last round of bad weather.
Wind entering the garage of this house may have caused the roof blowout above it. Photo credit: Carrie Stevenson
However, there’s good news that work that can be done to help protect a home during storms. Hardening homes through “windstorm mitigation” techniques can prevent updraft from strong winds. A house is only as strong as its weakest area, and those are typically the connections between the walls, roof, and foundation. A wind-rated garage door and/or brace are crucial, as strong winds can enter a garage and blow out the roof above it.
When strong winds enter a home, their force moving out can cause an updraft and lift off the roof. Graphic courtesy UF IFAS.
In Escambia and Santa Rosa County, the local nonprofit “Rebuild Northwest Florida” operates a cost-sharing program to help residents harden homes. After the tornado in Century (near the Alabama border in north Escambia County), engineers from Rebuild examined a home that suffered a direct hit from a tornado. The home had been retrofit with crucial wind mitigation techniques and sustained no structural damage. Buildings, sheds, and homes all around it were destroyed. Examples of several wind mitigation techniques, including storm shutters, wind-rated windows, garage door braces and a tornado shelter are available for public viewing at the Escambia County Extension office in our windstorm mitigation building.
As the spring storm season heats up and rolls into hurricane season, keep in mind these suggestions for both the landscape and home. As always, contact your local Extension office if you have any questions.
by Matt Lollar | Jan 27, 2016
We may be suffering from the recent low temperatures, but temperate fruit trees such as peaches and apples require a period of cold weather in order to become cold hardy and produce a good crop.
What is Cold Hardiness?
Cold hardiness is the ability of a plant to survive low temperatures. However, every cold event is fairly unique with variables such as when the low temperatures occur (early vs. late winter), how quickly the temperature drops, the temperatures in the days leading up to the event, and the length of time the low temperatures are sustained.
Cold Acclimation
Cold acclimation is the development of freezing tolerance in plants. Three fall environmental factors contribute to cold acclimation in fruit trees. Plant will develop 10 to 15 degrees of cold tolerance when the leaves sense shorter day lengths. Metabolic activity is increased when days are short and temperatures are between 60°F days and 40°F nights. The second factor occurs when lows reach the 20s, which can make trees up to 10 degrees hardier. The final factor occurs when temperatures dip to near zero, which fortunately for us does not occur very often.
Trees remain hardy during the winter as long as temperatures remain fairly stable. However, de-acclimation occurs in reaction to warm temperatures. This explains the winter flowering which occurred this past December. A cold snap may not injure trees unless it immediately follows a period of mild temperatures.
Florida Average Chill Hours Map – UF/IFAS Extension
Chilling Requirement
The cold weather and gradual cold acclimation are necessary to a tree’s accumulation of chill hours which is necessary for steady fruit yields. Chill hours are the accumulation of hours when temperatures are between 32°F and 45°F. The yearly average chill hour accumulation in Northwest Florida is between 660 and 700 hours. The apple varieties recommended for our area (‘Anna’, ‘Dorsett Golden’, and ‘TropicSweet’) have a chilling requirement of 250 to 300 hours. Some of the peach varieties recommended for our area (‘Flordacreast’, ‘Flordaking’, and ‘Gulfsnow’) have a chilling requirement of 350 to 400 hours. Please note the risk of planting these varieties because their chilling requirements are lower than our average chill hour accumulation. The varieties listed are for example, but other available varieties are suitable for our area.
Whether you like winter weather or not, just remember the satisfaction of eating fresh fruit in the summer. To track this year’s chill hours from the warmth of your home, please visit the AgroClimate tool at http://agroclimate.org/tools/Chill-Hours-Calculator/.
by Larry Williams | Jan 13, 2016
Pecan trees are well adapted to our area, making beautiful large shade trees. And, if the correct varieties are planted, they can provide pecans.
Only those pecan varieties that show some real resistance to disease problems are recommended for planting here in the humid south. Select grafted trees of Desirable, Curtis, Elliott, Moreland or Stuart varieties.
Pecan leaves and fruit. Photo credit: Brad Haire, University of Georgia, Bugwood.org
Obtain and plant your pecan trees during the winter – December through February. Purchase trees that are three to six feet tall. Larger trees are more difficult to transplant.
Give pecan trees plenty of room to grow. The distance between trees should be approximately sixty feet because mature trees are quite large. Commercial producers sometimes use a closer spacing, primarily because they are using varieties that will bear at an earlier age. But most of those varieties do not have good disease resistance and still require pesticide spray at times. Homeowners will not have the needed equipment to spray a large pecan tree and the drift from such sprays would not be desirable around your home, so commercial varieties aren’t recommended for home plantings.
One of the keys to survival of a pecan tree is not allowing the root system to dry out before, during or after transplanting. Regular watering will be required for a period of at least six months or until the young tree is well established. The planting hole should be 18 to 24 inches wide and only as deep as the root system. Spread the roots so they are not matted together. The planting depth is critical. Place at such a depth that the uppermost root is at or near the soil surface. Excessively deep planting can result in eventual death of the tree.
When planting your tree, there is no need or advantage to using peat moss, compost, manure or other organic matter in the planting hole. Plant the tree in the native soil without amendments.
Do not fertilize when the tree is planted. Wait until May of the first year after planning to apply fertilizer.
Remember that pecan trees are large at maturity, with branches spreading 30 feet or so from the trunk. Also, because of the brittle limbs and failing nuts, it’s best not to plant these trees too near the home, driveway or sidewalk.
by Sheila Dunning | Dec 16, 2015
Though the calendar says December, the weather in Northwest Florida fluctuates between winter and spring temperatures. The nice days are wonderful opportunities to accomplish many of those outside landscape chores in preparation for spring. But, it is also a good time to start planning for next month’s colder temperatures. Since we don’t experience frozen soil, winter is the best time to transplant hardy trees and shrubs. Deciduous trees establish root systems more quickly while dormant; versus installing them in the spring with all their tender new leaves. Here are a few suggestions for tasks that can be performed this month:
- Plant shade trees, fruit trees, and evergreen shrubs.
- Plant pre-chilled daffodil and narcissus bulbs (late December/early January).
- Do major re-shaping of shade trees, if needed, during the winter dormancy.
- Water live Christmas trees as needed and water holiday plants such as poinsettias as needed.
- Check houseplants for insect pests such as scale, mealy bugs, fungus gnats, whitefly and spider mites.
- Continue to mulch leaves from the lawn. Shred excess leaves and add to planting beds or compost pile.
- Replenish finished compost and mulch in planting beds, preferably before the first freeze.
- Switch sprinkler systems to ‘Manual’ mode for the balance of winter.
- Water thoroughly before a hard freeze to reduce plants’ chances of damage.
- Water lawn and all other plants once every three weeks or so, if supplemental rainfall is less than one inch in a three week period.
- Fertilize pansies and other winter annuals as needed.
- Protect tender plants from hard freezes.
- Be sure to clean, sharpen and repair all your garden and lawn tools. Now is also the best time to clean and have your power mower, edger and trimmer serviced.
- Be sure the mower blade is sharpened and balanced as well.
- Provide food and water to the area’s wintering birds.
