Although blackberries are well adapted to North Florida, many different biotic and abiotic factors can impact fruit production. Photo by Molly Jameson.
Diagnosing Abiotic Blackberry Fruit Disorders
Whether it be wild blackberries you’ve foraged or a prized cultured variety you’ve oh-so-carefully sustained, we are now in prime blackberry season, and there are many sweet, tangy delectable fruits to be eaten.
Blackberry bushes are well adapted to the Florida Panhandle and the plants can be found growing all over – along roadways, in ditches, throughout open fields, and also within forests.
Although wild blackberries and domesticated cultivars thrive in our climate, there is a wide range of factors that could affect blackberry fruiting. When diagnosing plant problems, we tend to blame insects and diseases, but there are many abiotic (non-living) factors that could negatively impact blackberry fruit production. If your blackberry drupelets (the small subdivisions that comprise a blackberry fruit) are compromised, you may be experiencing one or more of the following abiotic blackberry disorders.
Although blackberries can self-pollinate, insect pollination is critical for forming the best blackberries. Photo by Johnny N. Dell, Bugwood.org.
Poor Pollination. Blackberries, strangely enough, are not true berries botanically. True berries only have one ovary per flower (such as bananas, watermelons, and avocados!). Each blackberry flower contains over 100 female flower parts, called pistils, that contain ovaries. To form a fully sized blackberry with many drupelets, at least 75% of the ovaries need to be pollinated. While blackberries can self-pollinate, pollinator insects, such as bees, are very important to ensure adequate drupelet formation. When weather conditions are overly cloudy and rainy, bees are less active. If this coincides with blackberry flowering, you may end up with some blackberries that are nearly drupe-less.
White Drupe. If you notice patches of white and brown drupelets on your most sun-exposed canes, you might have white drupe disorder. When humidity drops and temperature heats up, solar radiation contacting your berries is more powerful, as there is less moisture in the air to deflect the intense heat. Berries that are not protected by leaf coverage, and those on trellises oriented for maximum sun exposure, are most vulnerable to white drupe damage.
Sunscald. Often associated with white drupe, sunscald is most common when temperatures are extreme. Daytime highs in the Florida Panhandle in June and July regularly reach 90°F, if not higher. At these times, fruit exposed to the sun can be hotter than the air temperature around them, which essentially cooks the fruit. As I suspect you’d prefer to cook your fruit after harvest in preparation for blackberry pie, orient your trellis so it gets shade relief during the hottest part of the day and harvest often.
Diagnosing a blackberry issue can be challenging, as there can be more than one culprit impacting the fruit. Photo by Molly Jameson.
Red Cell Regression. One of the not-so-well understood abiotic blackberry disorders is red cell regression, or red drupelet disorder. If you’ve ever harvested blackberry fruit and stored them in the refrigerator for later munching, you may think your eyes are deceiving you when you discover your fruit doesn’t appear as ripe as when you picked it. This regression in color is linked to rapid temperature change, but rest assured, it does not affect the sugar content of the fruit. There are a few things you can do if you think this is affecting your berries, such as harvesting in the morning when the berries are still cool, harvesting when the sky is overcast, or shading your berries pre-harvest. You can also try to cool your berries in stages, perhaps moving from the field, to shade, to A/C, and then to the fridge.
Beyond abiotic stresses, blackberries can also suffer from insect, pest, and disease damage, such as from stink bugs, beetles, mites, birds, anthracnose, leaf rust, crown gall, and beyond. For domesticated blueberry bushes, proper cultivar selection, site selection, planting technique, fertilization, irrigation, propagation, and cane training is important and will allow the plants to grow healthy to defend themselves against any abiotic or biotic nuisance that comes their way.
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.
Wildflowers near Live Oak, Florida. Image Credit, UF / IFAS
Florida (“land of flowers” in Spanish) is and has always been full of flowers, and countless civic and public organizations work diligently to protect and promote the beauty of our natural ecosystems. Did you know that the Florida Wildflower Foundation works with the Florida Department of Transportation (FDOT) to preserve wildflower areas on state-maintained roads throughout Florida? This effort really took off in the 1960’s when non-native Crimson clover started sprouting among sod planted by the state FDOT, and has grown into a much larger statewide initiative. The state wildflower license plate program provides funding for these efforts.
Wildflower areas along highways not only improve beauty on the roadsides, but provide habitat for countless pollinator insects that drive our $1.2 billion (annual) citrus and agricultural industries and our own backyard landscapes. In addition, leaving no-mow areas along highways saves money on mowing costs, reduces soil erosion, and improves air quality.
The state wildflower license plate supports wildflower preservation efforts statewide. Photo credit: Florida Wildflower Foundation
Wildflower viewing is typically best in the spring and fall, and particularly in areas (such as state parks and forests) that have been recently managed by prescribed fire. Many low-lying areas are home to beautiful native species such as pitcher plants, hibiscus, and meadowbeauty. Be very careful when viewing or stopping to see roadside wildflowers, and be sure to find designated parking areas to prevent accidents. To find a map of the wildflower trails, visit your local tourism bureau or go online at https://flawildflowers.org/protect/.
Currently, every Panhandle county from Jefferson County east has designated wildflower areas. The Escambia County Board of Commissioners passed a wildflower ordinance supporting the program, and a committee met in May 2019 to determine more areas of the county appropriate to set aside for the program. As opposed to planting new wildflowers, the program prioritizes conserving roadside areas that already support healthy wildflower populations. If you know of good candidates for preservation on state roads in Escambia or any other panhandle county, please contact me (ctsteven@ufl.edu) or Liz Sparks (liz.aparks57@gmail.com) with the Florida Wildflower Foundation.
Each week, the editors scour the world wide web to find unique and informative content. This week’s selection is a video by Tennessee State University Extension Agent Joellen Dimond, in which she explains how to create a backyard butterfly garden!
Blooming amaryllis flower. Photo by Logan Boatwright
Are you tired of seeing only green from your shrubs such as boxwood or yew? Are the areas next to your home walls, fences, terraces, tree islands, gate entrances, and/or borders barren? Do you want to add color to these areas? You may want to consider planting these areas with the beautiful amaryllis (Hippeastrum x hybridum).
Amaryllis grows from a tough, dependable bulb that will bloom during the spring after winter dormancy. The strap-shaped leaves will emerge first and grow about 1.5 inches wide, up to three feet long, and persist much of the year in Florida. They are reduced later in the summer and ultimately die back from frost.
In the late winter, bulbs will eventually produce one to three leafless stalks, or scapes, that will each have two or more trumpet-shaped flowers. Flowers come in a variety of forms and shapes: from single and double, miniature or large. Flower colors can be red, bright pink, shades of pink, orange, white, rose, or even salmon. It does not stop there! The flowers may even be striped and multi-colored. Amaryllis can create a striking focal point when they are planted in clusters of 10 or more of similar color.
Double flowers of amaryllis. Photo by Logan Boatwright.
Amaryllis may be planted anytime of the year, but winter is best. They are sun- and shade-tolerant, but planting in light shade is best since leaves will yellow in full sun and plants bloom poorly in heavy shade. Amaryllis prefer well-drained sites to prevent bulb and root rots.
For the best amaryllis performance, till and amend the soil with a 3- to 4-inch layer of organic matter and 2 to 3 pounds of 6-6-6, or a comparable amount of other complete fertilizer per 100 square feet. Plant 12 to 15 inches apart. Amaryllis can greatly benefit from at least one fertilizer application in the early spring and two to three applications during the growing season.
Many blooms from multiple amaryllis bulbs. Photo by Logan Boatwright.
After flowering it’s a good practice to remove the stalks, unless seeds for planting are desired. If the bulbs become crowded, dig and separate them out. Doing this will encourage large, uniform flowers.
Looking to add something to brighten your landscape this autumn? Firespike (Odontonema strictum) is a prolific fall bloomer with red tubular flowers that are very popular with hummingbirds and butterflies. It’s glossy dark green leaves make an attractive large plant that will grow quite well in dense shade to partial sunlight. In frost-free areas firespike grows as an evergreen semi-woody shrub, spreads by underground sprouts and enlarging to form a thicket. In zones 8 and 9 it usually dies back to the ground in winter and resprouts in spring, producing strikingly beautiful 9-12 inch panicles of crimson flowers beginning at the end of summer and lasting into the winter each year. Firespike is native to open, semi-forested areas of Central America. It has escaped cultivation and become established in disturbed hammocks throughout peninsular Florida, but hasn’t presented an invasive problem. Here in the Panhandle, firespike will remain a tender perennial for most locations. It can be grown on a wide range of moderately fertile, sandy soils and is quite drought tolerant. Firespike may be best utilized in the landscape in a mass planting. Plants can be spaced about 2 feet apart to fill in the area quickly. It is one of only a few flowering plants that give good, red color in a partially shaded site. The lovely flowers make firespike an excellent candidate for the cutting garden and is a “must-have” for southern butterfly and hummingbird gardens. Additional plants can be propagated from firespike by division or cuttings. However, white-tailed deer love firespike too, and will eat the leaves, so be prepared to fence it off from “Bambi”.
