Plant with Purpose at the Leon County Extension Office

Plant with Purpose at the Leon County Extension Office

Plant with Purpose: Written by Rachel Mathes

Last spring, we were all ready to host another Open House and Plant Sale on Mother’s Day weekend. When the realities of the pandemic became clear, we canceled the event for the safety of everyone involved. We typically have more than 500 visitors and dozens of volunteers on site. This year we are happy to announce we have adapted our annual fundraiser to a monthly learning and growing opportunity for the whole community.

growing milkweed

Master Gardener Volunteer Jeanne Breland is growing native milkweed in her monarch exclusion fortress for a Plant with Purpose talk and sale in the spring. Previous years’ milkweed have been eaten by monarch caterpillars before the sale so Jeanne has built her fortress to get the best results. Photo by Rachel Mathes

Our Master Gardener Volunteers will be teaching Thursday evening classes on particular plant groups throughout the year in our new series: Plant with Purpose. Topics will range from milkweed to shade plants to vegetables and herbs for different seasons. Attendees can attend the talks for free and grow along with us with the purchase of a box. These boxes are modeled after community supported agriculture (CSA) boxes you can purchase from local farms. Buyers will get a variety of the plants discussed in the plant lesson that week.  For example, in our first event, Growing a Pizza Garden, we will have two tomato plants, two pepper plants, and one basil plant available for $20. Throughout the year, prices and number of plants will vary depending on the topic.

We hope with this new model of presentations and plant sales will enable us to remain Covid-safe while still bringing horticulture education to the community. Classes will be held on Thursday evenings from 6-7 pm via Zoom. Register on our Eventbrite to get the Zoom link emailed to you before each talk. Plant pick up will be the following Saturday from 10 am to noon. Master Gardener Volunteers will load up your plant box in a contact-free drive thru at the UF/IFAS Leon County Extension Office at 615 Paul Russell Rd.

propagation table

Propagation of angel wing begonia and other plants by Joan Peloso, Master Gardener Volunteer.

Master Gardener Volunteers are already growing plants for you to purchase throughout the year. Landscape plants, herbs, vegetables, shrubs and even trees will be available later in the year. Funds raised from this series help fund our Horticulture programming. Some notable programs that will benefit from Plant with Purpose include our Demonstration Garden, 4-H Horticulture Club, the Veterans’ Garden Group at the VA Tallahassee Outpatient Clinic, and various school gardens we help support throughout Leon County.

In the last year, we have adapted many of our programs to meet virtually, and even created new ones like our Wednesday Webinar series where we explore different horticulture topics twice a month with guest speakers from around the Panhandle. While we still can’t meet in person to get down in the dirt with all of our community programs, we hope that the Plant with Purpose series will help fill the hole left by our cancelled Open House and Plant Sale. Join us for the first installment of Plant with Purpose on Thursday March 18th from 6-7pm. Pick up for purchased plant boxes will be Saturday March 20th from 10am-noon.

To register for this event and other events at the Leon County Extension Office, please visit the Leon County Extension Office Events Registration Page.

Fruit Tree Grafting Tips and Scion Selection

Fruit Tree Grafting Tips and Scion Selection

It’s mid-February, cloudy, and cold. It’s time to get outside and take cuttings for fruit and nut tree grafting. The cuttings that are grafted onto other trees are called scions. The trees or saplings that the scions are grafted to are called rootstocks. Grafting should be done when plants start to show signs of new growth, but for best results, scion wood should be cut in February and early March.

Scion Selection

Straight and smooth wood with the diameter of a pencil should be selected for scions. Water sprouts that grow upright in the center of trees work well for scion wood.  Scions should be cut to 12-18″ for storage. They should only need two to three buds each.

Scions

Scions ready for grafting. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

Scion Storage

Scions should be cut during the dormant season and refrigerated at 35-40°F until the time of grafting. If cuttings are taken in the field or far from home, then simply place them in a cooler with an ice pack until they can be refrigerated. Cuttings should be placed in a produce or zip top bag along with some damp paper towels or sphagnum moss.

Grafting

It is better to be late than early when it comes to grafting. Some years it’s still cold on Easter Sunday. Generally, mid-March to early April is a good time to graft in North Florida. Whip and tongue or bench grafting are most commonly used for fruit and nut trees. This type of graft is accomplished by cutting a diagonal cut across both the scion and the rootstock, followed by a vertical cut parallel to the grain of the wood. For more information on this type of graft please visit the Grafting Fruit Trees in the Home Orchard from the University of New Hampshire Extension.

Bench Graft

A bench graft union. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

Achieving good bench graft unions takes skill and some practice. Some people have better success using a four-flap or banana graft technique. This type of graft is accomplished by stripping most of the bark and cambium layer from a 1.5″ section of the base of the scion and by folding the back and removing a 1.5″ section of wood from the top of the rootstock.  A guide to this type of graft can be found on the Texas A&M factsheet “The Four-Flap Graft”.

Grafting is a gardening skill that can add a lot of diversity to a garden. With a little practice, patience, and knowledge any gardener can have success with grafting.

Why Are My Oranges Sour?

Why Are My Oranges Sour?

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.

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.

A graphic of various citrus greening symptoms. Photo Credit: University of Florida/IFAS Extension

Pawpaw – A Fruit with an Identity Crisis

Pawpaw – A Fruit with an Identity Crisis

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 in the woods.

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

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.

Plant Propagation Tips

Plant Propagation Tips

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:

  1. How much time and money is available?
  2. Is a uniform crop desired or is trait variation preferred?
  3. 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.

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.

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.

Loquat – An Attractive Small Tree That Bears Tasty Fruit

Loquat – An Attractive Small Tree That Bears Tasty Fruit

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.

Loquat Tree

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.

Loquat Flowers with Honey Bee

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.