by Matthew Orwat | Feb 14, 2017
Dooryard citrus enthusiasts may be uncertain about late winter management of Satsuma and other citrus trees. Several questions that have come in to the Extension Office recently include:
- Should I prune my trees?
- Why are the leaves yellow?
- How soon should I fertilize?
The focus of this article is to provide some answers to these common questions.
Should I prune my trees?
This is a complicated question that is best answered with “it depends…” Pruning is not necessary for citrus, as it is in many temperate fruits, to have excellent production quality and quantity. Citrus trees perform excellently with minimal pruning. The only pruning necessary for most citrus is removing crossing or rubbing branches while shaping young trees, removing dead wood, and pruning out suckers from the root-stock. Homeowners may choose to prune citrus trees to keep them small, but this will reduce potential yield, since bigger trees produce more fruit.
Often, maturing Satsuma trees produce long vertical branches. It is tempting to prune these off, since they make the tree look unbalanced. To maximize yield, allow these branches to weep with the heavy load of fruit until they touch the ground. This allows increased surface area for the tree, since the low areas around the trunk are not bare. Additionally, weeds are suppressed since the low branches shade out weed growth. The ground under the trees remains bare, thus allowing heat from the soil to radiate up during cold weather events. The extra branches around the trunk offer added protection to the bud union as well. If smaller trees are desired for ease of harvest, ‘flying dragon’ root-stock offers dwarfing benefits, so that the mature scion cultivar size will only grow to 8-10 feet tall.
Heavy fruit loads were produced in many home gardens throughout Northwest Florida last year. When fruiting is heavy, citrus trees translocate nitrogen and other nutrients from older leaves to newer growth and fruit. Therefore, temporary yellowing may occur and last until trees resume growing in the spring. Remember, never fertilize after early September, since fertilizing this late in the year can reduce fruit quality and increase potential for cold injury. If a deficiency, as in the photo above persists through spring, consider a soil test, or consult a citrus production publication to determine if additional fertilizer should be added to your fertilizer program.
How soon should you fertilize?
Although most Florida citrus publications recommend fertilizing citrus in February, they don’t take into account the potential for late frost in the Panhandle. Thus it makes more sense to wait until mid-March for the first fertilizer application in this region. Citrus trees don’t require a fertilizer with a high percentage of nitrogen, so it is best for fruit quality if an analysis of around 8-8-8 with micro-nutrients is used. Fertilizer should be applied in the drip-line of the tree, not around the trunk. The drip-line of a mature tree is generally considered to extend one foot from the trunk out to one foot from the edge of the furthest branch tip from the trunk. For fertilizer quantity recommendation see the chart below.
Through awareness of the unique managements techniques inherent to dooryard citrus production in the Panhandle, home gardeners are offered an opportunity to provide their friends and family with a substantial portion of their annual citrus !
For more information on this topic please use the following link to the UF/IFAS Publication:
by Beth Bolles | Feb 14, 2017
Arapaho blackberry has chill requirements that match those received in our area. Photo by Beth Bolles, UF IFAS Extension
Many of us are enjoying warmer temperatures this winter, but many deciduous fruit crops really need cold temperatures in order to break dormancy for the year. In areas that experience cold temperatures, plants have evolved the ability to survive by slowing growth and protecting sensitive tissues by going dormant. In order to break out of dormancy and begin growth again, plants experience an amount of chill hours (temps between 32 and 45 degrees F) that is suitable for specific areas. In our area, we normally range between 400 and 600 chills hours.
If we choose a fruit plant whose chill requirements match the amount of chill in our area, the plant will generally resume growth when it is safe for buds and tender tissues to develop. If we choose a plant with chill requirements higher than the amount our area receives, then the plant is not signaled to break dormancy and we end up with very sparse growth and no fruit.
So far in the winter of 2016-17, some areas have not received ‘normal’ amounts of chilling temperatures. Common fruit like apple, peach, some blueberries, and certain selections of blackberries may be affected by this by not breaking out of dormancy. This can impact your flower and fruit formation. For commercial growers, it can impact the amount of fruit available and even fruit prices at markets.
Since fruit trees are an investment of time and money, these are not plants that can be easily replanted to match chill hours with changing weather patterns. Perhaps planting fruit crops with a range of chill hours required might be beneficial Your future decisions to grow fruit trees may include crops that don’t rely as much on chill hours to be successful. For more information, please consult the Dooryard Fruit Varieties guide from UF / IFAS Extension.
by Matthew Orwat | Jan 26, 2017
by Matthew Orwat | Dec 7, 2016
Fall 2016 Satsumas. Image Credit: Matthew Orwat
One question that repeatedly pops up in my Extension work is “When do I harvest fruit or vegetable X ?” This fall, the question of “when should I harvest my citrus?” has been a choice topic! The most common citrus in the Florida panhandle is the satsuma, Citrus unshiu, so it makes sense to limit this article to that species.
Harvesting satsumas can be a confusing activity for new citrus enthusiasts. Fall seasons in the panhandle tend to be extremely variable, from cold and wet to warm and dry or any combination thereof. To complicate matters, citrus is often grown in a protected microclimate in the garden. Thus, another variable is added to the decision tree.
Some harvest considerations to take note of:
- Sometimes the fruit is ready to harvest even when some green remains on the fruit
- Not all fruit on a given tree will be ready at the same time
- It’s a good idea to harvest a few fruit per tree and taste test….this will be a good indicator of the readiness of the other fruit on the tree
- A general trend to consider is that the longer the fruit remains on the tree, the sweeter it will become
Image Credit Matthew Orwat
When satsuma ripen, they become slightly soft. That’s a good indicator that they are ready to harvest. This softness makes them extremely easy to peel but poses a challenge when harvesting. If they are simply pulled off of the tree, some peel will be left on the tree and the fruit will be compromised. Such a fruit would have to be consumed quickly. To solve this problem satsuma are clipped off the tree, leaving a tiny bit of stem attached to the fruit. This allows the fruit to be stored and transported.
When a hard freeze is approaching (5 hours below 28ºF), it is important to harvest the fruit before this event whether or not they are ripe. Hard freezes will ruin the texture of the fruit and cause them to begin the rotting process.
Since a hard freeze is forecast for Friday December 9th 2016 for part of the Florida Panhandle, consult your local weather forecast and make your decisions accordingly. For an in-depth discussion on citrus fruit harvesting and cold tolerances, please consult this publication from Texas A& M University. Additional articles are available on cold protection and frost readiness here.
by Matthew Orwat | Oct 21, 2016
Image Credit: gardeningsolutions.ifas.ufl.edu
A recent visit to the North Florida Research and Education Center reminded me of a fruit that is often low profile in Northwest Florida, the Oriental persimmon. The Oriental, or Japanese, persimmon (Diospyros kaki) was introduced to the Southern United States in the mid to late 1800s. Although it is native to Japan and China, it is a close relative of the native persimmon Diospyros virginiana.
In the early 20th century the oriental persimmon was a popular fruit crop in Florida, but this industry declined due to marketing factors. The Oriental persimmon is still a viable fruit for home gardens.
Trees are available grafted onto local native persimmon rootstock, which enhances their ability to perform well in Northwest Florida soils.
Persimmons are divided into two types for the purposes of marketing: astringent and non-astringent. Astringent persimmons contain high concentrations of tannins which cause the mouth to pucker when eating the persimmon if it is not fully ripe. When fully ripe, they are rich and sweet, but very soft. Non-astringent cultivars can be picked hard and ripened for 7-10 days at room temperature. Non-astringent persimmons were developed in Japan and introduced to the U.S. market in the 1980s. These have become very popular with home gardeners since they can be eaten when firm, and have a crunchy texture. Persimmons are popular today in Asian cuisine and as a dessert, since they contain sugars at levels between 15 and 25%.
Persimmons have relatively few pests in Northwest Florida when compared to other higher maintenance fruits such as peaches and plums. Fungal leaf spot caused by species of cercospora, alternaria and anthracnose can cause premature defoliation. Fungicidal sprays are useful in controlling these diseases if they are at high enough levels to cause tree injury. The stem and branch fungus Botrysphaeria dothidia will cause deep, elongated branch lesions similar to canker. These openings invite borers into the tree and can lead to loss of the limb structure. The best defense against this problem is a good offense; a healthy tree will be less likely to be attacked by this fungus. Dormant sprays of copper or sulfur based fungicides can also help reduce the incidence of all fungal diseases.
Fully ripe persimmon, ready for a scoop of ice cream! (Image Credit Matthew Orwat)
The major insect pest of persimmon is scale. Thankfully, scale can be controlled with dormant oil or season all horticultural oil. Persimmon psylla can cause leaf deformation early in the season, but is not always a large enough problem to warrant control. Natural enemies often eliminate the need for chemical control. If control is necessary, several insecticides labeled for fruit trees will take care of the problem. Twig girdlers can lay eggs on persimmon stems in September and October, and once hatched, the insect can girdle the stem and the stem will die. To control this pest it is important to remove dead and infected wood each growing season.
Out of the non-astringent cultivars, Fuyu regularly rates as the most popular and reliable cultivar. It does require thinning, since it often sets too much fruit, which can cause branches to bend and break. A good practice is to thin out 50% of the fruit during years in which fruit set is heavy.
Below is a chart of different non-astringent persimmon cultivar characteristics from the IFAS Extension publication SP 101, from April 1994 by E.P. Miller, Biologist; T.E. Crocker, Professor, Horticultural Sciences Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.
Characteristics of non-astringent cultivars. SP 101, from April 1994 by E.P. Miller; T.E. Crocker,
For further information please consult the UF / IFAS publication ENH 388: Diospyros kaki: Japanese Persimmon and the previous Panhandle Agriculture article Oriental Persimmon Varieties for North Florida .
by Carrie Stevenson | Jul 26, 2016
Summer is full of simple pleasures—afternoon rainstorms, living in flip flops, and cooling off in a backyard pool. Among these, one of my favorites is walking out my door and picking handfuls of figs right from the tree. Before we planted our tree, my only prior experience with the fruit was a Fig Newton—I’d never eaten an actual fig, much less one picked fresh. Now, they are my favorite fruit.
When ripe, figs are a deep shade of pink to purple. Larger green figs will ripen over the course of a few days. Photo credit: Carrie Stevenson
Native to Asia Minor and the Mediterranean, figs were introduced to Florida in the 1500’s by Spanish explorers. Spanish missionaries introduced these relatives of the mulberry to California a couple hundred years later. Figs are best suited to dry, Mediterranean-type climates, but do quite well in the southeast. Due to our humidity, southern-growing figs are typically fleshier and can split when heavy rains come through. The biggest threats to the health of the trees are insects, disease (also due to our more humid climate) and root-knot nematodes.
Fig trees can grow quite large and produce hundreds of fruit each year. Photo credit: Carrie Stevenson
Our tree started out just a couple of feet tall, but 12 years ago we replanted it along a fence in our back yard. It has grown so large (easily 25 feet tall and equally wide) that it hangs over our driveway, making it handy to grab a few as I hop in the car to run errands. The tree is in full sun at the bottom of a slope, and seems to be a satisfied recipient of all the runoff from our backyard. This position has resulted in a thick layer of soil and mulch in which it thrives.
We usually see small green fruit start to appear in early May, becoming fat and ripe by the second half of June. The tree produces steadily through early August, when the tree’s leaves turn crispy from the summer heat and there’s no more fruit to bear. The common fig doesn’t require a pollinator, so only one tree is necessary for production. The fiber-rich fig is also full of calcium, potassium, and vitamins A, E, and K. As it turns out, the “fruit” is actually a hollow peduncle (stem) that grows fleshy, forming a structure called a synconium. The synconium is full of unfertilized ovaries, making a fig a container that holds both tiny flowers and fruit in one.
The insides of a fig show the small flowering structures that form the larger fruit. Photo credit: Carrie Stevenson
With the hundreds of figs we’ve picked, my family has made fig preserves, fig ice cream, baked figs and of course eaten them raw. We typically beg friends and neighbors to come help themselves—and bring a ladder—because we can’t keep up with the productivity. Often you can tell you’re near our tree from around the block, as the aroma of fermenting fruit baking on the driveway is far-reaching.
No matter what you do with them, I encourage planting these trees in your own yard to take full advantage of their sweet, healthy fruit and sprawling shade. As Bill Finch of the Mobile (AL) botanical gardens has written, “fresh…figs are fully enjoyed only by the family that grows them, and the very best figs are inevitably consumed by the person who picks them.”
