by Les Harrison | Feb 16, 2016
Last Week’s temperatures have confirmed the winter of 2016 is not 100% over. Now is the time to plan that spring garden!.
Garden catalogs from every part of the nation are finding their way into many area homes. Their pages promise the buyer the potential for legendary success and the envy of their friends and neighbors.
After all, who can resist the full color beauty of giant flowers, large luscious fruit and vegetables which are sure to win a prize at the fair? There is not a runt, reject or cull in all the pages of these publications offering the mortal version of horticultural heaven.
Before ordering, the would-be gardener should consider several factors to increase the likelihood of a positive gardening experience. A failure will waste not only funds, but also much time and hard work and may introduce a long-term problem or two.
Cultivar selection for a tree, shrub, vegetable or fruit is critically important to producing the desired results. While a specific plant cultivar may grow and produce in one environment, it may not do so in all situations.
A common example of this problem is grape vines offered. Only muscadine grapes will grow and produce locally because Pierce’s disease kills other varieties.
Carefully examine the growing zones recommended by the catalog for specific cultivars. Check with fellow gardeners and the UF/IFAS Extension Office to see if they have any information or experience with any cultivars under consideration.
Heirloom varieties are especially sensitive to the variances in growing conditions. While they offer unusual and sometimes unique taste and culinary traits or landscaping characteristics, these antique varieties can be a challenge to grow.
Their genetic potential can make a consistent yield, especially for the novice growers, a real effort. Also, as an open pollinator variety, the results can be inconsistent.
Another question for the catalog company customer is new or untried plants varieties. Some of these plants are patented and few or no trials have been performed with them in north Florida’s growing zone.
Caution should be used when ordering these seed or plants. Being the first in North Florida to cultivate a new variety may require a large commitment of time and resources, and may produce only a large disappointment.
Check with fellow gardeners, local nurseries and your UF/IFAS Extension Office for available information on these new or patented varieties. It may save much wasted motion.
Lastly, be sure the plant or seeds under consideration do not have the potential as exotic invasive pests. As hard as this may be to believe, this does occur.
Some catalog vendors will advise buyers in the ordering instructions or at the time of ordering. Either way, the purchaser should check to verify the plant ordered does not have the potential to escape control and damage the environment.
Check out the following publications to assist with finding adapted fruit and vegetable varieties for North Florida.
by Mary Salinas | Feb 16, 2016
As you have read in other articles in this blog, it is too early to fertilize your lawn; however, this is a good time to start fertilizing your citrus to ensure a healthy fruit crop later in the year.
Orange grove at the University of Florida. UF/IFAS photo by Tara Piasio.
Citrus benefits from regular fertilization with a good quality balanced citrus fertilizer that also contains micronutrients. A balanced fertilizer has equal amounts of nitrogen, phosphorus and potassium such as a 6-6-6, 8-8-8 or a 10-10-10. The amount of fertilizer to be applied will vary on the formulation; for example you will need less of a 10-10-10 than a 6-6-6 as the product is more concentrated. Always consult the product label for the correct amount to use for your particular trees. Fertilizer spikes are not recommended as the nutrients are concentrated in small areas and not able to be widely available to all plant roots.
The number of fertilizations per year will vary depending on the age of the tree. Trees planted the first year need 6 light fertilizations that year starting in February with the last application in October. In following years, decrease the number of fertilizations by one per year until the fifth year when it is down to 3 fertilizations per year. From then on, keep fertilizing 3 times per year for the life of the tree. Good quality citrus fertilizer will have accurate and specific instructions on the label for the amount and timing of fertilizer application.
Fertilizer should be spread evenly under the tree but not in contact with the trunk of the tree. Ideally, the area under the drip line of the tree should be free of grass, weeds and mulch in order for rain, irrigation and fertilizer to reach the roots of the tree and provide air movement around the base of the trunk.
If you have not in recent years, obtain a soil test from your local extension office. This can detect nutrient deficiencies, which may be corrected with additional targeted nutrient applications.
For more information:
Citrus Culture in the Landscape
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 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 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 Matthew Orwat | Nov 24, 2015
Satsuma fruit, harvested with their stem intact to ensure longevity when stored. Image Credit: Dr. Pete Andersen
The satsuma mandarin (Citrus unshiu) is a popular dooryard fruit tree, and emerging crop, across the Florida Panhandle. 100-150 years ago it was a major cash crop for the region, with boxcar loads being shipped to the Northeast during the months of October-December. Due to a series of hard freezes in the 1950s and a shift in land use from produce production to timber, the satsuma industry was effectively dead in northwest Florida until recent years, when several entrepreneurial growers have invested time and effort in bringing back this delicious citrus to the commercial scene.
Throughout this time, many homeowners have enjoyed this historic citrus, dressing many a Thanksgiving table with its beautiful bright orange fruit. Satsumas contain few seeds, are generally sweet and very easy to peel. They are part of the mandarin group of citrus, and somewhat resemble canned mandarin oranges in shape and flavor. The cooler the fall temperatures (above freezing) the sweeter the fruit will be at harvest.
Mature trees are hardy down to 14-18 º F when budded to a cold hardy rootstock such as trifoliate orange or swingle. Young trees need to be protected from temperatures below the mid 20s, and fruit will be ruined if exposed to any freezing temperatures below “light frost” conditions. Commercial growers use protective techniques, such as microirrigation, to protect their fruit if freezing temperatures threaten harvest.
This Thanksgiving, if you do not have a satsuma tree of your own, seek out a local producer and buy a case of satsumas for the holiday season !
For more information on growing and harvesting satsuma mandarins consult “The Satsuma Mandarin – HS195“, produced for your benefit by UF / IFAS Extension.
