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.

Drought-Tolerant Landscape Plants

Drought-Tolerant Landscape Plants

When we go through dry periods in North Florida some residents become interested in drought-tolerant plants to include in their landscapes. The need for irrigation can be reduced when drought-tolerant plants are used. But don’t overuse these plants. Remember we have periods of rainy weather, too.

Gulf Muhly Grass in Flower

Gulf Muhly Grass in Flower. Photo credit: Larry Williams

Some drought-tolerant plants have poor tolerance to the other extreme – too much water. There are a few plants that can tolerate both extremes but they are the exception. Avoid using drought-tolerant plants on naturally wet or poorly drained sites. But if you have the typical deep sandy well drained soil Florida is famous for, you’d do well to include some drought-tolerant plants on your site.

Drought-tolerant plants are especially well suited for areas that receive little to no irrigation.

Some plants are genetically better able to withstand drought. They have a built-in tolerance of drought. Many of our Florida native plants are designed to grow in our poor water holding sandy soils. Many of the plants native to arid areas of the world possess high drought-tolerance. These plants have characteristics that allow them to better survive dry weather. These features include thicker or waxier leaves, large surface root areas or deep roots and the ability to drop leaves in drought and regain them when moisture is adequate.

Beautyberry with clusters of bright purple berries

Beautyberry with fruit. Photo credit: Larry Williams

It’s important to realize that these plants must first establish a root system before they can cope with severe dry weather. Plan to irrigate during dry periods for the first season to allow them to become established.

Some outstanding trees to consider include crape myrtle, redbud, Chinese pistache, cedar (Cedrus species), hawthorn (Crataegus species), American holly, yaupon holly, Southern red cedar (Juniperus species), Live oak, Sand live oak, winged elm, pond cypress and bald cypress. Some people are surprised to learn that pond cypress and bald cypress have high drought-tolerance because these trees are associated with swamps, many times growing in standing water. But once established on a dry site, they exhibit very good drought-tolerance.

Some outstanding shrubs with drought-tolerance include glossy abelia, dwarf yaupon holly, Indian hawthorn (Rhaphiolepis species), beauty berry (Callicarpa americana), pineapple guava, junipers, oleander, spiraea, blueberry or sparkleberry (Vaccinium species), viburnum, Chaste tree (Vitex agnus-castus) and coontie (Zamia pumila).

Close up of pineapple guava in bloom

Pineapple guava in bloom. Photo credit: Larry Williams

Some outstanding drought-tolerant groundcovers to consider include beach sunflower (Helianthus debilis), daylily, juniper, lantana, liriope, rosemary (Ceratiola ericoides), Asiatic jasmine and society garlic. Many of the ornamental grasses such as Gulf muhly are good choices as well.

For more ideas on developing a Florida-friendly, water wise landscape, contact the UF/IFAS Extension Office in your County or visit the below website. https://ffl.ifas.ufl.edu/index.html

Fungi Species Also Enjoying our Recent Weather

Fungi Species Also Enjoying our Recent Weather

tree leaves

Symptoms of oak leaf blister on swamp chestnut oak. Credit: Gordon Magill.

Even during global pandemics, it’s a joy to be outside during the great north Florida spring we’ve been experiencing lately. As cold fronts come through with their rain bands, some packing a punch, they leave behind the most pleasant mornings, clear blue daytime skies, and crisp evenings. Unfortunately, we’re not the only organism that also enjoys those cool days. Many species of fungi are quite active this type of year as the rains, followed by warmer, yet not too hot temperatures, create the perfect conditions for fungal growth. Some of these fungi grow right on or in the plants we’d like to be enjoying for ourselves, stealing nutrients and causing plant decline or merely causing aesthetic damage. As this is an active time for certain species of fungi, local extension offices are getting more calls and questions regarding lawn and landscape damage due to fungal pathogens. A recent call was a new one for me and an example of a native fungi-plant interaction that looks bad but requires no intervention from us. It also highlights how correctly identifying a disease leads to the best action and can often save time and money and prevent unnecessary pesticides (in this case a fungicide) from entering the environment.

blister on oak leaf

Close up of oak leaf blister on swamp chestnut oak. Credit: Gordon Magill.

The fungi and plant involved here was the oak leaf blister (Taphrina caerulescens) on a swamp chestnut oak (Quercus michauxii). It forms, you guessed it, blisters on the leaves of any of the oaks, though live oak (Quercus virginiana), laurel oak (Quercus laurifolia), and water oak (Quercus nigra) seem to be preferred hosts. The spores of the fungi, dormant since the previous summer/fall and which happen to get lodged in bud scales through wind and rain, germinate in cool, wet weather. The fungus then infects young leaves as they flush and its growth causes a disruption in the leaves’ development. This leads to the blistered look of the leaf tissue and, during extended periods of cool, wet weather, the entire leaf sort of shrivels, browns, and eventually falls off. Spores are eventually released from the fallen leaves to start the process over the next spring.

shriveled leaf

Severe oak leaf blister on swamp chestnut oak. Credit: Gordon Magill.

Though the leaves look pretty terrible, this fungal disease rarely causes plant health issues and the tree recovers just fine. Specimen trees that experience it year to year may be treated with a fungicide, but most homeowners can just let it go. Raking up and disposing of the leaves may help prevent further infections by reducing the number of spores released in the area.

As you enjoy another cool morning after an evening rainstorm, remember that the fungi all around you are also having a great day. You may want to look at your landscape plants and see if there’s anything abnormal going on. If so, take a photo and send it to your local extension office for help with identification and best methods of control, or, like in this case, just leaving it alone.

p.s. As I said this was a new one for me and I want to thank Stan Rosenthal, Extension Agent emeritus, for assisting with identification.

Why Let Your Own Backyard be a Source of Worry?

Why Let Your Own Backyard be a Source of Worry?

In times like these, it seems that our own perceived “problems” pale in comparison to the “big picture.”  In my day-to-day work, I have the opportunity to help people solve problems with their landscapes, lawns and gardens. I enjoy the problem solving part of my job as an extension agent.

Lawn with winter annual weeds in early spring

Winter annual weeds in lawn in early spring. Photo credit: Larry Williams

You’d be surprised how upset some people can be about a few weeds, a dying petunia or a tomato with a crack in it. They’ll let small things like this upset their entire world. It’s as if they think we live in a perfect world when it comes to expectations for the plants in their own landscape.

It has become apparent to me that too many people spend too much time letting too many small things bother them too much.

When my twin sister, Linda, and I were growing up in a small town in middle Georgia, an elderly couple (Mr. and Mrs. Hunt) would crack pecans and give the shelled halves to us to eat. They’d hand the shelled pecans to us over the fence that separated our yards. At five or six years old this was a treat for my sister and me.

I remember their landscape. I remember Mrs. Hunt sweeping their dirt driveway lined with coconut sized rocks. She used handmade brooms. I remember their pink flowering dogwoods in spring. I remember their old-fashioned yellow and orange daylilies during summer. I remember the fascination of seeing red spider lilies seemingly come from nowhere in the fall underneath deciduous trees as they displayed their autumn colors. I remember Mrs. Hunt letting me smell a flower from a sweetshrub plant, which reminded me of sweet apples. The deep red blooms and dark green leaves of this shrub complemented the white wooden wall on the east side of their home.

Mulberry tree with fruit

Mulberry tree with fruit. Photo credit: Larry Williams

I remember climbing a large mulberry tree in their backyard and picking and eating the berries. I remember watching Mr. Hunt prune grapevines growing on an overhead trellis. I remember learning about the history of a ginkgo tree planted just outside a chicken pin in their side yard. I remember watching hummingbirds flying in and out of the reddish orange funnel-shaped blooms of a large trumpet vine growing on an old metal frame of a water tank.

I don’t remember the weeds, even though I know there must have been weeds in the Hunt’s landscape. I know there was the occasional pecan that didn’t fill out or that was worm infested. And I’m sure an occasional plant had to be replaced. But these are not the things that made lasting impressions for me.

The big picture is not the weeds, the dying petunia plant or the pecan with a worm in it. Sure you will have weeds in your yard and certain plants that don’t survive. Just don’t let these things become the source of worry. In my opinion, a landscape should be a source of pleasure, a place to learn and a place to pass along lasting memories.  Besides, with all the things there are to worry about in this world (as recent days have revealed), why let your own backyard be one of them?

What are these bumps on my pecan trees?

What are these bumps on my pecan trees?

I was recently sent some pictures of some unusual growths on pecan tree leaves.  At first glance, the growths reminded me of the galls caused by small wasps that lay their eggs on oak leaves.  However, after a little searching it became apparent this wasn’t the case.  These galls were caused by the feeding of an aphid-like insect known as phylloxera.

Leaf galls caused by pecan phylloxera.

Leaf galls caused by pecan phylloxera. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

The feeding from the phylloxera causes the young leaf tissue to become distorted and form a gall that encloses this female insect called a “stem mother”.  These insects are rarely seen, but the hatch from over-wintering eggs in March/April just after budbreak.  Once hatched, these “stem mothers” crawl to the new leaves and begin feeding.  Once the gall forms, they start to lay eggs inside the gall.  The eggs hatch inside the gall and the young phylloxera begin to feed inside the gall and the gall enlarges.  The matured insects break out of the gall in May and some will crawl to new spots on the leaves to feed and produce more galls.

Pecan stem damage from phylloxera.

Pecan stem damage from phylloxera. Photo Credit: University of Georgia

There are two common species of phylloxera that infect the leaves.  The Pecan Leaf Phylloxera seems to prefer young trees and the Southern Pecan Leaf Phylloxera prefers older trees. The damage from each of these insects is nearly indistinguishable.  Damage from these insects is usually not severe and merely an aesthetic issue.

Once the damage is discovered on a tree, it is too late to control the current year’s infestation.  There are currently no effective methods for control of phylloxera in home gardens.  Soil drench applications witha product containing imidacloprid have been limited in their effectiveness.

Sustainable Forestry in Florida

Sustainable Forestry in Florida

photo of biologist on a ladder next to a pine tree

A biologist at Blackwater State Forest monitors endangered woodpecker habitat in a longleaf pine. Photo credit: Carrie Stevenson, UF IFAS Extension

In the Southeastern United States, our forests were once primarily longleaf pine-dominated ecoystems. Frequent summer thunderstorms and their accompanying lightning strikes would routinely set a portion of the forest afire. With plenty of space to move, wild animals relocated to safer portions of the forest or hunkered down in deep, winding gopher tortoise burrows underground. The longleaf pine’s life cycle has co-evolved with fire in such a way that its young growth stage is resistant to fire, and its success as a species requires fire to open up the canopy.

As human populations grew larger in the South, much of that forest land was harvested for timber, pitch, and turpentine, then cleared for agriculture and urban development. The American Southeast now has only 5% of that original longleaf pine forest. Thankfully, continued efforts led by organizations like the Longleaf Alliance and The Nature Conservancy have reminded folks of the species’ importance, and led to conservation and restoration efforts.

University of Florida Extension Agent surveys a planted forest with a producer in Washington County. UF/IFAS Photo: Josh Wickham.

Now, we have a newer mix of forest cover, with specimen trees preserved in parks and yards. In addition, we also have sustainable tree farms. You may have passed a wooded area where you noticed pine trees (mostly loblolly and slash in the south) were in perfect rows—these are being farmed, planted in rows just like any other crops. While they will be harvested eventually, during their lifetimes these trees fulfill all the roles we appreciate in wild forests–animal  habitat, oxygen production, carbon dioxide uptake, and cooling via transpiration. The other positive of sustainable forestry is that almost as soon as they’re cut, they’re replaced. Trees are grown in a stepwise fashion to ensure there is always an available harvest. Multiple generations are grown at once to ensure there is rarely a truly bare spot in the landscape.

With 17 million acres in production, forestry makes up the largest agricultural commodity in Florida. When managing, planting, and harvesting trees, modern foresters take tree physiology, invasive species, disease outbreaks, and genetics into serious consideration. These professionals help produce necessary items for life; wood for construction, furniture, books, and the all-important toilet paper, which has emerged as a bartering item in the time of COVID-19. For more information on forestry in Florida, visit the University of Florida’s School of Forest Resources and Conservation.