by Matt Lollar | Oct 8, 2019
Last week at the Panhandle Fruit and Vegetable Conference, Dr. Ali Sarkhosh presented on growing pomegranate in Florida. The pomegranate (Punica granatum) is native to central Asia. The fruit made its way to North America in the 16th century. Given their origin, it makes sense that fruit quality is best in regions with cool winters and hot, dry summers (Mediterranean climate). In the United States, the majority of pomegranates are grown in California. However, the University of Florida, with the help of Dr. Sarkhosh, is conducting research trials to find out which varieties do best in our state.
In the wild, pomegranate plants are dense, bushy shrubs growing between 6-12 feet tall with thorny branches. In the garden, they can be trained as small single trunk trees from 12-20 feet tall or as slightly shorter multi-trunk (3 to 5 trunks) trees. Pomegranate plants have beautiful flowers and can be utilized as ornamentals that also bear fruit. In fact, there are a number of varieties on the market for their aesthetics alone. Pomegranate leaves are glossy, dark green, and small. Blooms range from orange to red (about 2 inches in diameter) with crinkled petals and lots of stamens. The fruit can be yellow, deep red, or any color in between depending on variety. The fruit are round with a diameter from 2 to 5 inches.
Fruit, aril, and juice characteristics of four pomegranate cultivars grown in Florida; fruit harvested in August 2018. a) ‘Vkusnyi’, b) ‘Crab’, c) ‘Mack Glass’, d) ‘Ever Sweet’. Photo Credit: Ali Sarkhosh, University of Florida/IFAS
A common commercial variety, ‘Wonderful’, is widely grown in California but does not perform well in Florida’s hot and humid climate. Cultivars that have performed well in Florida include: ‘Vkusnyi’; ‘Crab’; ‘Mack Glass’; and ‘Ever Sweet’. Pomegranates are adapted to many soil types from sands to clays, however yields are lower on sandy soils and fruit color is poor on clay soils. They produce best on well-drained soils with a pH range from 5.5 to 7.0. The plants should be irrigated every 7 to 10 days if a significant rain event doesn’t occur. Flavor and fruit quality are increased when irrigation is gradually reduced during fruit maturation. Pomegranates are tolerant of some flooding, but sudden changes to irrigation amounts or timing may cause fruit to split.
Two pomegranate training systems: single trunk on the left and multi-trunk on the right. Photo Credit: Ali Sarkhosh, University of Florida/IFAS
Pomegranates establish best when planted in late winter or early spring (February – March). If you plan to grow them as a hedge (shrub form), space plants 6 to 9 feet apart to allow for suckers to fill the void between plants. If you plan to plant a single tree or a few trees then space the plants at least 15 feet apart. If a tree form is desired, then suckers will need to be removed frequently. Some fruit will need to be thinned each year to reduce the chances of branches breaking from heavy fruit weight.
Anthracnose caused by Colletotrichum sp. to pomegranate fruit. Photo Credit: Gary Vallad, University of Florida/IFAS
Anthracnose is the most common disease of pomegranates. Symptoms include small, circular, reddish-brown spots (0.25 inch diameter) on leaves, stems, flowers, and fruit. Copper fungicide applications can greatly reduce disease damage. Common insects include scales and mites. Sulfur dust can be used for mite control and horticultural oil can be used to control scales.
by Matthew Orwat | Sep 17, 2019
Fall Pruned Azalea. Image Credit Matthew Orwat
Although Northwest Florida is well known for its beautiful Azalea displays every spring, many do not understand that these shows of bloom could be sacrificed completely by pruning at the wrong time.
Pruning Azaleas in the fall will result in a loss of spring bloom the following spring, since flower buds are initialized on previous year’s growth for most azalea cultivars.This means that they flower on growth put on throughout the previous growing season. If a gardener removes the previous season’s new growth, they are removing the blooms as well.
So, when is the proper time to prune Azaleas? The ideal time to prune is directly after the spring bloom. This will give the plant enough time to generate abundant new growth, thus maximizing bloom next spring. One might think that when growing the repeat blooming Encore azaleas, pruning time doesn’t matter. Should the need arise to prune these compact, repeat blooming shrubs the optimal time is directly after spring bloom and not after the final fall bloom cycle.
For more information on pruning Azaleas or on general Azalea culture, please read the UF / IFAS publication Azaleas at a Glance or check out the Pruning Azalea page on Gardening Solutions.
by Beth Bolles | Aug 7, 2019
We are always on the lookout for an attractive plant for our landscape. At the nursery, some plants have a more difficult time gaining our attention. They may not be as showy, possessing neither colorful flowers nor bold foliage. In these cases, we could be missing out on low maintenance plant that offers its own form of beauty in the right landscape spot.
One plant that I love is the Japanese plum yew (Cephalotaxus harringtonia), especially the spreading form ‘Prostrata’. In the nursery container, this plant is nothing special but once established in the landscape it performs well. The conifer type leaves are an attractive dark green and the ‘Prostrata’ selection is low growing to about 2 to 3 feet. An advantage too is that growth is slow so it won’t take over or require routine pruning.
Japanese plum yews grow best in partial shade and once established will be fine with rainfall. For a shadier side of the home, the spreading plum yew has a place as an evergreen foundation plant too.
Japanese plum yew in a shaded garden. Photo by Beth Bolles, UF IFAS Extension Escambia County
If the ‘Prostrata’ selection is too low growing for you, consider the ‘Fastigiata’ cultivar that will grow upright to about 8 feet with a 5 foot spread.
A year old planting of upright Japanese plum yew in filtered light. Photo by Beth Bolles, UF IFAS Extension Escambia County
by Daniel J. Leonard | May 20, 2019
Spring is a wonderful time of year. After months of dreariness and bare branches, bright, succulent green leaves and flowers of every kind and color have emerged. So too, have emerged gardeners and outdoor enthusiasts ready to tackle all their home and landscape improvement projects planned over the winter. However, this is also the time, when folks first start paying attention to their plants again, that strange, seemingly inexpiable plant problems crop up!
All plant problems can be divided into two categories: biotic problems, or issues caused by a living organism (think insects, fungus, and bacteria), and abiotic problems, issues that arise from things other than biotic pests. It’s the first category that people generally turn to when something goes wrong in their landscape or garden. It’s convenient to blame problems on pests and it’s very satisfying to go to the local home improvement store, buy a bottle of something and spray the problem into submission. But, in many of my consultations with clientele each spring, I find myself having to step back, consider holistically the circumstances causing the issue to arise, scout for pests and diseases, and if I find no evidence of either, encouraging the person to consider the possibility the problem is abiotic and to adopt patience and allow the problem to correct itself. Of course, this is never what anyone wants to hear. We always want a solvable problem with a simple cause and solution. But life isn’t always that easy and sometimes we must accept that we (nor a pest/disease) did anything wrong to cause the issue and, in some cases, that we ourselves actually caused the problem to happen in the first place! To illustrate, let’s consider two case studies from site visits I’ve had this spring.
Cold damage on Boxwood hedge
Three weeks ago, I got a call from a very concerned client. She had gotten her March issue of a popular outdoor magazine in the mail, in which was a feature on an emerging pathogen, Boxwood Blight, a nasty fungus decimating Boxwood populations in states north of us. She had also noticed the Boxwoods in front of her house had recently developed browning of their new spring shoots across most the hedgerow. Having read the article and matching the symptoms she’d noticed to the ones described in the magazine article, she was convinced her shrub was infected with blight and wanted to know if there was a cure. Agreeing that the symptoms sounded similar and wanting to rule out an infection of an extremely serious pathogen, I decided to go take a look. Upon inspection, it was obvious that Boxwood Blight wasn’t to blame. Damage from disease generally isn’t quite as uniform as what I saw. The new growth on top of the hedge was indeed brown but only where the eaves of the house and a nearby tree didn’t provide overhead cover and, to boot, the sides of the hedge were a very normal bright green. Having gone through a recent cold snap that brought several mornings of heavy frost and knowing that the weeks before that the weather had been unseasonably warm, causing many plants to begin growing prematurely, all signs pointed toward an abiotic problem, cold/frost damage that would clear up as soon as the plant put on another flush of growth. The client was delighted to hear she didn’t have a hedge killing problem that would require either adopting a monthly fungicide regime or replacing the hedge with a different species.
Damage to ‘Sunshine’ Ligustrum from pressure washing siding with bleach.
The very next week, another client asked if I would come by her house and take a look at a hedge of ‘Sunshine’ Ligustrum that lines her driveway, whose leaves had “bleached” out, turning from their normal chartreuse to a bronzy white color. This time, having seen similar issues with this particular plant that almost always involved an infestation of Spider or Broad Mites, I figured this was a cut and dry case that would end with a call to her pest control company to come spray the offending bugs. However, though the leaf damage looked similar, I was not able to locate any existing pests or find evidence any had been around recently, rather it appeared the leaves had been exposed to something that “bleached” and burned them. Puzzled, I began asking questions. What kind of maintenance occurs on the plants? Have you fertilized or applied any chemicals recently? Nothing. Then, near the end of our conversation, the client mentioned that her neighbor had pressure washed their house on a windy day and that she was irritated because some of the soap solution had gotten on her car. Bingo. Leaf burn from pressure washing solution chemicals. This time I was guilty of assuming the worst from a pest when the problem quite literally blew in on the wind from next door. Again, the client was relieved to know the plant would recover as soon as a new flush of growth emerged and hid the burned older leaves!
This spring, I’d encourage you to learn from the above situations and the next time you notice an issue on plants in your yard, before you reach for the pesticides, take a step back and think about what the damage looks like, thoroughly inspect the plants for possible insects or disease, and if you don’t find any, consider the possibility that the problem was abiotic in nature! And remember, if you need any assistance with identification of a landscape problem and want research-based recommendations on how to manage the problem, contact your local UF/IFAS Extension office.
by Mark Tancig | Mar 6, 2019
Azaleas are a beautiful shrub for the north Florida landscape, especially if pruned properly. Source: Larry Williams, UF/IFAS
The sight of azaleas in the north Florida spring just makes you feel good. They are so vibrant, and with such variation, that you can’t take your eyes off them. As an appreciator of these beautiful displays of color, nothing pains me more than to see an improperly pruned azalea during this time. If you must prune your azaleas, please, please only prune them once a year and only soon after flowering has ended! This public service announcement will hopefully ensure we all get to see the full azalea show. Otherwise, we’ll be left with mostly green hedges, some flowers uncomfortably tucked in the interior of the plants, or flowers poking out the sides like a middle-aged man’s balding head.
If pruned properly and at the right time, this azalea shrub would be a mass of flowers. Source: Mark Tancig, UF/IFAS.
The common flowering azaleas in landscaped settings are native to Japan and a relative of blueberries. They comprise many different hybrids, cultivars, and varieties of plants in the genus Rhododendron (Greek for rose-tree) and have been cultivated for centuries. Long ago, I’m sure, those who studied plants and tinkered with azaleas realized that their vegetative growth (new leaves and stems) ends soon after flower bud initiation. This means that later prunings, or multiple prunings throughout the year, will be taking off more developing flower buds than new leaf and stem growth.
To prevent depriving us all of less flowers, consider why – or if – they need pruning in the first place. Proper planning and planting can prevent azaleas, which naturally want to be a sprawling shrub, from growing into the sidewalk or driveway. If you’ve inherited azaleas that may be the right plant, but slightly in the wrong place, they can be heavily pruned every couple of years to keep them in check, and can even be transplanted. Azaleas are not a good choice for formal hedges. If given the right place and enough space, the only required pruning would be dead, diseased, or crossing branches.
If you decide you need to prune – whether to knock back for space or for general shape – only bust out the loppers once the flowers have withered on the ground… and then lock those loppers away so that you won’t be tempted. If you have landscapers working for you, remind them to keep the hedge trimmers away from the azaleas.
Azaleas are vibrant, even in black and white! Source: Florida State Archives, Florida Memory Project.
For the love of flowers, please prune azaleas thoughtfully, and share this information with others
P.S. We also have several species of native azaleas (including Rhododendron austrinum and Rhododendron canescens) that can be a beautiful addition to the landscape.
by Matt Lollar | Dec 17, 2018
Fatsia japonica, common name Japanese aralia, provides tropical texture to your landscape. That coarse texture is attributed to its large (nearly a foot wide) leaves that are deeply lobed (maple leaf shaped). This shade-loving plant performs well in moist (not soggy) locations. Upright stems originate near ground level usually near the base of older stems. The stems grow to about eight feet tall before bending toward the ground under their own weight.
Even though the foliage of this species is enough to make you want it in your own garden, you will absolutely fall in love with its blooms. Upright clusters of showy, creamy white flowers begin to appear in fall. These little snowballs provide wonderful color to your garden. The shiny, black fruits appear in winter and are prominent for several weeks. The fruit are know to attract birds to the landscape.
A Fatsia japonica specimen in full bloom. Photo Credit: Matt Lollar, University of Florida/IFAS Extension
Fatsia japonica thrives in the shade in slightly acidic, nutrient-rich, moist soil. Older stems become leggy and can be cut back to encourage branching. In the right place, Fatsia japonica is low-maintenance and not typically bothered by pests. It is also known to perform well in coastal landscapes. It fits well in entryways, in containers, or in mass plantings spaced three feet apart.
