by Matt Lollar | Nov 4, 2020
From time to time we get questions from clients who are unsatisfied with the flavor of the fruit from their citrus trees. Usually the complaints are because of dry or fibrous fruit. This is usually due to irregular irrigation and/or excessive rains during fruit development. However, we sometimes get asked about fruit that is too sour. There are three common reasons why fruit may taste more sour than expected: 1) The fruit came from the rootstock portion of the tree; 2) The fruit wasn’t fully mature when picked; or 3) the tree is infected with Huanglongbing (HLB) a.k.a. citrus greening or yellow dragon disease.
Rootstock
The majority of citrus trees are grafted onto a rootstock. Grafting is the practice of conjoining a plant with desirable fruiting characteristics onto a plant with specific disease resistance, stress tolerance (such as cold tolerance), and/or growth characteristics (such as rooting depth characteristics or dwarfing characteristics). Citrus trees are usually true to seed, but the majority of trees available at nurseries and garden centers are grafted onto a completely different citrus species. Some of the commonly available rootstocks produce sweet fruit, but most produce sour or poor tasting fruit. Common citrus rootstocks include: Swingle orange; sour orange; and trifoliate orange. For a comprehensive list of citrus rootstocks, please visit the Florida Citrus Rootstock Selection Guide. A rootstock will still produce viable shoots, which can become dominant leaders on a tree. In the picture below, a sour orange rootstock is producing a portion of the fruit on the left hand side of this tangerine tree. The trunk coming from the sour orange rootstock has many more spines than the tangerine producing trunks.
A tangerine tree on a sour orange rootstock that is producing fruit on the left hand side of the tree. Photo Credit: Matt Lollar, University of Florida/IFAS Extension
Fruit Maturity
Florida grown citrus generally matures from the months of October through May depending on species and variety. Satsumas mature in October and taste best after nighttime temperatures drop into the 50s. Most tangerines are mature in late November and December. Oranges and grapefruit are mature December through April depending on variety. The interesting thing about citrus fruit is that they can be stored on the tree after becoming ripe. So when in doubt, harvest only a few fruit at a time to determine the maturity window for your particular tree. A table with Florida citrus ripeness dates can be found at this Florida Citrus Harvest Calendar.
Citrus Greening
Citrus Greening (HLB) is a plant disease caused by the bacterium Candidatus Liberibacter asiaticus, which is vectored by the Asian citrus psyllid. The disease causes the fruit to be misshapen and discolored. The fruit from infected trees does not ripen properly and rarely sweetens up. A list of publications about citrus greening can be found at the link Citrus Greening (Huanglongbing, HLB).
A graphic of various citrus greening symptoms. Photo Credit: University of Florida/IFAS Extension
by Matt Lollar | May 20, 2020
The pawpaw (Asimina triloba) is a native edible that is often overlooked and misunderstood. Not only does it produce a delicious fruit that looks like a mango and tastes like a banana, but it is also an aesthetic landscape plant. This fruit is slowly gaining popularity with younger generations and a handful of universities (Kentucky State University and the University of Missouri) are working on cultivar improvements.
A pawpaw tree growing in the woods. Photo credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
The pawpaw is native to the eastern United States (USDA Plant Hardiness Zones 5-8), however it’s closest relatives are all tropical such as the custard apple, cherimoya, and soursop. The pawpaw, along with these fruits, are known for their custard-like texture which may be a unpleasant for some consumers. Pawpaws are relatively hardy, have few insect pests, and can still produce fruit in partial shade (although they produce more fruit when grown in full sun).
Pawpaws perform best in moist, well-drained soils with a pH between 5.5 and 7.0. They are found growing wild in full to partial shade, but more fruit are produced when trees are grown in full sun. However, pawpaws need some protection from wind and adequate irrigation in orchard settings. Trees can grow to between 12 feet to 25 feet tall and should be planted at least 15 feet apart. In the Florida Panhandle, flowers bloom in early spring and fruit ripen from August to October depending on variety and weather.
Young pawpaw fruit growing on a small tree. Photo Credit: Matt Lollar, University of Florida/IFAS Extension at Santa Rosa County
A number of improved cultivars of pawpaws have been developed that produce more fruit with more flavor than native seedlings/saplings. The University of Missouri has conducted trials on the following pawpaw cultivars: ‘Sunflower’; ‘PA Golden’; ‘Wells’; ‘NC-1’; ‘Overleese’; ‘Shenandoah’; ‘Susquehanna’; and ’10-35′. Most of these cultivars performed well in southern Missouri, however yields may differ in the Florida Panhandle. The full results of the trial can be found in the “Pawpaw – Unique Native Fruit” publication.
Pawpaws can be propagated by seed or cuttings. Unlike most fruit trees, pawpaws are usually true to seed meaning that saved seed produces a tree with similar characteristics to the parent tree. To save seeds, place fresh seeds in a bag of moist peat moss and refrigerate for 3 to 4 months before planting. To vegetatively propagate, take cuttings (pencil thin in diameter) in the winter and store in a refrigerator until early spring. Cuttings should be chip budded onto seedling rootstock during the spring. Please visit this publication from the University of Nebraska for more information on chip budding.
Pawpaw fruit are ready to harvest when they are slightly soft when gently squeezed. Fruits picked prior to being fully ripe, but after they start to soften, will ripen indoors at room temperature or in a refrigerator. Already-ripe fruit will stay fresh for a few days at room temperature or for a few weeks in the refrigerator. To enjoy pawpaw fruit throughout the year, scoop out the flesh, remove the seeds, and place the flesh in freezer bags and freeze.
Whether you want to add more native plants to your landscape or you are a rare and unusual fruit enthusiast, pawpaw may be the tree for you. They can be utilized as a focal point in the garden and provide delicious fruit for your family. For more information on pawpaw or other fruit trees, please contact your local Extension Office.
by Matt Lollar | Mar 20, 2020
It’s always fun to add new plant to the landscape. And it’s even more fun to propagate your own plant material. The question is, what plant propagation method is best? The answer depends on a number of factors such as:
- How much time and money is available?
- Is a uniform crop desired or is trait variation preferred?
- What is the plant species being propagated?
Plants can be propagated either by seed (sexual propagation) or by segments of vegetative material (asexual propagation). Sexual propagation takes far less time and effort because new plants are being started from the seeds (offspring) of parent plants. This type of propagation promotes genetic diversity because offspring may not have the exact characteristics of the parent plants. Sexual propagation increases the possibility of hybrid vigor, which is the improved quality of plant material to that of parent plants. Asexual propagation usually takes more time, but generally ensures that propagated plants will maintain the same characteristics as the parent plant. For some species it may be the only way to pass on desired traits to subsequent generations and it may be the only way to propagate certain species. A plant produced vegetatively can become larger than a plant produced by see in the same amount of time.
Tips for Successful Sexual Propagation
- Seed Collection – Seeds should be collected when fruit is ripe, just before they fall to the ground. In general, seeds should be cleaned, dried, and stored at 40 degrees Fahrenheit (in a refrigerator). However, palm seeds should be planted immediately after harvesting and cleaning.
- Seed Dormancy – Some seeds have thick seed coats the inhibit germination. Some seeds need to be scarified (breaking of the seed coat) and/or stratified (stored in a specific environment) in order to germinate.
- Seed Sowing – Seeds can be germinated in flats or other suitable containers in a seed starting media. Seeds should be planted at a depth of two to three times their diameter, but no deeper than 3 inches. Cycad seeds should be planted just below the medium surface.
Seeds stored in an envelope. Photo Credit: University of Florida/IFAS
Tips for Successful Asexual Propagation – In general, asexual propagation is the propagation of plant material from cuttings of stems, leaves, and/or roots.
- Rooting Hormones – Increase rooting percentage, hasten root initiation, increase the number of roots per cutting, and increase root uniformity. Auxin based rooting hormones (Indolebutyric acid (IBA) and Naphthalenacetic acid (NAA)) are available in dry or liquid forms. It is important to use the correct concentration for the particular plant species because over application can cause damage to cutting base.
- Sticking Cuttings – Cuttings should be stuck in the medium only deep enough to support the cuttings and hold them upright (1/2″ to 1″ deep).
- Post-Rooting Care – Fertilization should be applied as soon as roots emerge from the cuttings. However, overfetilization can increase soluble salts and burn roots.
Examples of Asexual Propagation
- Softwood Cuttings – Taken from woody plants usually three to four weeks after a new flush of growth. Commonly propagated species using this method include: crape myrtle; magnolia; oleander; azalea; jasmine; and boxwood.
- Semihardwood Cuttings – Similar to softwood cuttings, but the lower portion of the cutting has become lignified (woody). Usually taken from new shoots six to nine weeks after a flush of growth. Commonly propagated species using this method include: camellia; pittosporum; junipers; and some hollies.
- Hardwood Cuttings – Taken from the previous season’s growth, just before or during the dormant period. Commonly propagated species using this method include narrow-leaved evergreens and deciduous species during the dormant season after leaves have dropped.
- Leaf Cuttings – Comprised of only the leaf blade or the leaf blade and petiole (leaf stalk). Cuttings are stuck upright in the propagation medium with the basal end (petiole end) of the leaf inserted into the propagation medium. Commonly propagated species using this method include begonias and peperomias.
- Root Cuttings – Taken in late winter or early spring from two to three-year-old plant material. Plants propagated by root cuttings may not reproduce true to type if they are budded or grafted. Commonly propagated species using this method include: plumbago; bayberry; oakleaf hydrangea; and yucca.
Plants being propagated by leaf cuttings. Photo Credit: University of Florida/IFAS
This article provides only a brief overview of propagation methods and techniques. For more information on plant propagation please visit University of Florida Plant Propagation Glossary or Plant Propagation Techniques for the Florida Gardener. Please be advised that some plant material is patented and it is illegal to propagate patented material without written authorization or licensing of the patent holder. If it is patented, a notation of patent number will be on the tag.
by Matt Lollar | Dec 10, 2019
Loquat trees provide nice fall color with creamy yellow buds and white flowers on their long terminal panicles. These small (20 to 35 ft. tall) evergreen trees are native to China and first appeared in Southern landscapes in the late 19th Century. They are grown commercially in subtropical and Mediterranean areas of the world and small production acreage can be found in California. They are cold tolerant down to temperatures of 8 degrees Fahrenheit, but they will drop their flowers or fruit if temperatures dip below 27 degrees Fahrenheit.
A beautiful loquat specimen at the UF/IFAS Extension at Santa Rosa County. Photo Credit: Matt Lollar, University of Florida/IFAS – Santa Rosa County
Leaves – The leaf configuration on loquat trees is classified as whorled. The leaf shape is lanceolate and the color is dark green with a nice soft brown surface underneath. These features help give the trees their tropical appearance.
Flowers – 30 to 100 flowers can be present on each terminal panicle. Individual flowers are roughly half an inch in diameter and have white petals.
Fruit – What surprises most people is that loquats are more closely related to apples and peaches than any tropical fruit. Fruit are classified as pomes and appear in clusters ranging from 4 to 30 depending on variety and fruit size. They are rounded to ovate in shape and are usually between 1.5 and 3 inches in length. Fruit are light yellow to orange in color and contain one to many seeds.
A cluster of loquat flowers/buds being pollinated by a honey bee. Photo Credit: Matt Lollar, University of Florida/IFAS – Santa Rosa County
Propagation – Loquat trees are easily propagated by seed, as you will notice as soon as your tree first bears fruit. Seedlings pop up throughout yards containing even just one loquat tree. It is important to note that the trees do not come true from seed and they go through a 6- to 8-year juvenile period before flowering and fruiting. Propagation by cuttings or air layering is more difficult but rewarding, because vegitatively-propagated trees bear fruit within two years of planting. Sometimes mature trees are top-worked (grafted at the terminal ends of branches) to produce a more desirable fruit cultivar.
Loquat trees are hardy, provide an aesthetic focal point to the landscape, and produce a tasty fruit. For more information on growing loquats and a comprehensive list of cultivars, please visit the UF EDIS Publication: Loquat Growing in the Florida Home Landscape.
by Mary Salinas | Jul 11, 2019
Ripening thornless blackberries. Photo credit: Mary Salinas, UF/IFAS Extension.
To everyone’s delight, the blackberries are ripening in the Santa Rosa County Extension demonstration garden. The blackberry patch is a reliable perennial that continues to provide fresh berries year after year. Before you decide against them because you don’t want a thorny and painful hazard in your landscape, remember that there are thornless blackberry cultivars with fruit just as tasty as the old-fashioned thorny blackberry varieties. However, it is important to take care and make sure that the variety or cultivar you choose is adapted to our Florida climate and chill hours.
Blackberries bloom and produce fruit on last year’s canes. This year’s growth (the bright green shoot in the front center) will produce next year. Photo credit: Mary Salinas, UF/IFAS Extension.
You can choose a blackberry variety from your local nursery or propagate some plants from a favorite blackberry grown by a friend or neighbor (with permission, of course). Methods of propagation include stem cuttings, root cuttings, tip layering and removing the suckers that arise from the roots.
Plant when the weather is cooler in winter and choose a sunny spot with good soil. Frequent irrigation is crucial during the establishment period and when the fruit is produced. Weed control with organic or plastic mulches is also important to the success of your blackberry patch.
For more information on blackberry cultivars, propagation and growing success please see the University of Florida publication The Blackberry.
by Julie McConnell | Jun 21, 2019
My obsession with plants started with the purchase of my first house in Waverly, Alabama in the late 90s. I bought a house with seven acres and of that about 1.5 acres was a fenced yard. The landscape was not very appealing, so I was on a mission to make it beautiful yet functional for my dogs. The only problem was, as a new homeowner, I had very little expendable income for my burgeoning plant habit. This dilemma forced me to be a resourceful gardener.
Shop the discount rack at garden centers
- Many retail garden centers (especially mixed use stores with limited plant space) will discount plants simply because they are no longer flowering. Plants look perfectly healthy but are just not considered “retail ready” anymore, so rather than hold them over until they bloom again and appeal to most shoppers the stores tend to mark them down.
- Plants are either growing or they are dead, so it is common to find some outgrowing their container and are getting “potbound” which means the root system is outgrowing the pot. Potbound plants are hard to keep watered without wilting and the solutions are to transition to a larger pot or plant in the ground. Most garden centers are not equipped to pot up overgrown plants to larger containers, so the easier solution is to sell them quickly. If you purchase a plant with circling roots be sure to trim the bottom and score (slice) the root ball to encourage roots to spread laterally.
- Avoid plants that appear diseased (leaf spots, brown stems, mushy parts, rotting odor) or have active feeding insect activity.
Compliment other gardeners’ plants
- When you get gardeners together, they inevitably start swapping plants. I really don’t have an explanation for this other that good old southern hospitality, but I’ve noticed over the years that when you express appreciation of plants to other people they tend to end up in your own yard. Ask if you can take a pinch (for cuttings) or offer to divide a clump of crowded perennials and you are on your way to a trunk full of plant babies.
- I can’t recommend this for multiple safety reasons, but I have been known to photographs plants in my travels then strike up a conversation with a homeowner who insisted I take one home.
Experiment with basic propagation techniques
- Grow flowers from seed. Either purchase seeds (usually under $2/pack) or collect seed heads from spent flowers in your own garden. After flowers fade, allow them to set seed then either crush and distribute in other parts of your garden or store in a cool, dry place until you can swap with friends.
- Division – clumping perennials such as daylilies, cast iron plant, iris or liriope can be dug up and cut into smaller pieces with a shovel or machete. You only need to be sure to have buds on top and roots on the bottom to make a new plant. Other plants create offshoots that can be removed from the parent plant. Examples of these are agave, cycads, and yucca.
- Cuttings – the list of plants that can be propagated from stem cuttings is endless but a few that are very easy are crape myrtle, hydrangea, and coleus.
- Patented plants can not be propagated.
For more information read Plant Propagation Techniques for the Florida Gardener or contact your local UF/IFAS Extension Office.
