Kiwis – A Golden Opportunity

Kiwis – A Golden Opportunity

Kiwi Vines

Twisted and tangled kiwifruit plants in a North Florida orchard. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

When we think of kiwis, we think of fuzzy, slightly tart, egg-shaped fruits from somewhere in the Southern Hemisphere.  However, there is a species (Actinidia chinensis) of kiwi with smooth skin, sweet taste, and golden color.

Commonly available cultivars of this species are ‘AU Golden Dragon’ and ‘AU Golden Sunshine’.  Most years, kiwis won’t produce much of a crop in North Florida because they won’t receive enough chill hours, but they might be fun to try for the adventurous gardener.

  • Site Selection – Kiwis perform best in well-drained soils with a neutral pH (around 7.0).  High winds may cause canes to break and scar fruit, so a windbreak is recommended or they can be planted near a structure.
  • Irrigation – Kiwis need a lot of water during the summer.  This is partly due the their large leaves that transpire rapidly because of surface area.  Newly planted kiwis should be watered deeply at least once a week.
  • Fertilization – Fertilize kiwis three times a year (January, April, and June).  Do not apply fertilizer after the month of July to reduce the incidence of cold injury in the winter.
  • Insects and Diseases – The most common insects of kiwis are mites and scales.  To reduce the incidence of disease, plant kiwis at least 15 feet apart and train on a trellis.
  • Training – A T-bar trellis, similar to the system used to train grape vines, or a pergola should be used to provide support for the plants.  Once the plants are established (2 to 3 years after planting), about a third of the vines should be removed each year.
T-bar Trellis

An illustration of a T-bar trellis system. University of Georgia Extension

Kiwis are wind- and insect-pollinated.  Good growing conditions and insect pollination help increase fruit size.  Male and female plants are required for good fruit yields.  At least one male (pollen producing) plant should be planted for every four female (fruit producing) plants.

Kiwi plants will soon be planted for evaluation at the West Florida Research and Education Center in Jay, FL.  Please stay tuned for future data!  For more information on growing kiwis in the Southeast, please visit these webpages:

Kiwifruit Production Guide

Bringing Home the Gold – Auburn horticulture alum gets kiwifruit orchard off the ground in Reeltown

 

Is it Winter or is it Spring?

Is it Winter or is it Spring?

Ice on satsuma fruit in January 2014 in Crestview, Florida

Ice on Satsuma fruit from January 2014 ice storm in Crestview, FL. Photo credit: Larry Williams

Northwest Florida winters can be a rollercoaster ride of temperatures. One week it dips to freezing for a short time and the next week it rises to spring-like temperatures. We need to hold on for this ride of up and down temperatures but not over react too soon.

Following the sudden ride down to the lower temperatures, we may think winter is over. But we don’t see the next drop in temperatures that’s coming, as we are experiencing the ride upwards in temperatures.

On average, it’s not until we reach mid-March that we expect our last killing frost. A killing frost is heavy enough to kill tender plant growth. And, we can have light frosts well into the latter part of March and into early April. This is particularly true in the more northern portions of our Panhandle Counties.

The main point is to not get spring fever too early and encourage new plant growth by pruning or fertilizing too soon.

When landscape plants freeze, the first impulse may be to get out the pruning shears and cut away dead and dying leaves and branches. But this isn’t a good idea. Pruning can force new tender growth that is more likely to be injured by the next freeze. And, you can’t tell how much damage has been done until plants start new growth in spring. If you prune immediately after a freeze, you may cut away live wood that doesn’t have to be lost. Also, leaves and branches, which have been killed, can help protect the rest of a plant

Cold injury to lawn

Cold injury to lawn that happened March 31 in Crestview, FL. Photo credit: Larry Williams

against further cold injury.

Some people want to “jump start” their lawns before our weather will allow our grasses to grow. Waiting allows for more efficient use of the lawn fertilizer. You will not injury your lawn by

waiting but you can certainly injure your lawn by fertilizing too early.

So, have patience, allow your lawn to green up on its own and then fertilize, even if it’s not until April or May.

Finally, be a little philosophical. If you do lose one or two of your tender ornamentals, so what? Worse things could happen. And now you have a chance to add something new, perhaps some species native to our area that are not as subject to cold damage.

Even with this winter/spring rollercoaster ride, with thousands of plants to choose from and a generally mild climate, who can complain?

 

Fatsia japonica Provides Gorgeous Winter Blooms

Fatsia japonica Provides Gorgeous Winter Blooms

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.

Fatsia japonica Blooming

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.

 

Post Hurricane Landscape Care:  Replant Smartly with Hurricane Resistant Trees

Post Hurricane Landscape Care: Replant Smartly with Hurricane Resistant Trees

After a devastating windstorm, as we just experienced in the Panhandle with Hurricane Michael, people have a tendency to become unenamored with landscape trees.  It is easy to see why when homes are halved by massive, broken pine trees; pecan trunks have split and splayed, covering entire lawns; wide-spreading elms were entirely uprooted, leaving a crater in the yard.  However, in these times, I would caution you not to rush to judgement, cut and remove all trees from your landscape.  On the contrary, I’d encourage you, once the cleanup is over and damaged trees rehabilitated or disposed of, to get out and replant your landscape with quality, wind-resistant trees.

First, it’s helpful to take a step back and remember why we plant and enjoy trees and the important role they play in our lives.  Beyond the commercial aspect of farmed timber, there are many reasons to be judicious with the chainsaw in the landscape and to plant anew where seemingly sturdy trees once stood.  For example, trees provide enormous service to homes and landscapes, from massive cooling effects to aesthetic appeal.  Take this thermal satellite image of Hurricane Michael’s path that simultaneously shows the devastation of a major hurricane and the role trees play in the environment.

Lightly shaded area showing higher ground temperatures from loss of vegetation.

In the lighter colored areas where the wind was strongest and catastrophic tree damage occurred, the ground temperatures are much higher than the unaffected areas.  Lack of plant life is entirely to blame.  Plants, especially trees, provide enormous shading effects on the ground that moderate ground temperatures and the process of transpiration releases water vapor, cooling the ambient air.  Trees also lend natural beauty to neighborhood settings.  There is a reason people termed the hardest hit areas by Michael “hellscapes”, “warzones”, etc.  Those descriptions imply a lack of vegetation due to harsh conditions.  In this respect, trees soften the landscape with their foliage colors and textures, create architecture with their height and shape, and screen people from noise, unpleasant sights and harsh heat.

Though all trees give us the benefits outlined above, research conducted by the University of Florida over a span of ten major hurricanes, from Andrew to Katrina, shows that some trees are far more resistant to wind than others and fare much better in hurricanes.  In North Florida, the trees that most consistently survived hurricanes with the least amount of structural damage were Live Oaks, Cypresses, Crape Myrtle, American Holly, Southern Magnolia, Red Maple, Black Gum, Sycamore, Cabbage Palm and a smattering of small landscape trees like Dogwood, Fringe Tree, Persimmons, and Vitex.  If one thinks about these trees’ growth habits, broad resistance to disease/decay, and native range, that they are storm survivors comes as no surprise.  Consider Live Oak.  This species originated along the coastal plain of the Southeastern United States and have endured hurricanes here for several millennia.  Possessing unusually strong wood, they have also developed the ability to shed the majority of their leaves at the onset of storms.  This defense mechanism leaves a bare appearance in the aftermath but allows the tree to mostly avoid the “umbrella” effect other wide crowned trees experience during storms and retain the ability to bounce back quickly.  Consider another resistant species, Bald Cypress.  In addition to having a strong, straight trunk and dense root system, the leaves of Bald Cypress are fine and featherlike.  This leaf structure prevents wind from catching in the crown.  Each of the other listed species possess similar unique features that allow them to survive hurricanes and recover much more quickly than other, less adapted species.

Laurel Oak split from weak branching structure.

However, many widely grown native trees and exotic species simply do not hold up well in tropical cyclones and other wind events.  Pine species, despite being native to the Coastal South, are very susceptible to storm damage.  The combination of high winds and beating rains loosens the soil around roots, adds tremendous water weight to the crown high off the ground, and puts the long, slender trunks under immense pressure.  That combination proves deadly during a major hurricane as trees either uproot or break at weak points along the trunk.  In addition to pines, other widely grown native species (such as Pecan, Laurel Oak and Water Oak) and exotic species (such as Chinese Elm) perform poorly in storms.  Just as the trees that survive storms well possess similar features, so do these poor performers.  We’ve already mentioned why pines and hurricanes don’t mix well.  Pecan, Laurel Oak, and Water Oak tend to have weak branch angles and break up structurally in wind events.  The broad spreading, heavy canopy of trees like Chinese Elm cause them to uproot and topple over.  It would be advisable when replanting the landscape, to steer clear of these species or at least site them a good distance from important structures.

This piece is not a warning to condemn planting trees in the landscape; rather it is a template to guide you when selecting trees to replant.  Many of our deepest memories involve trees, whether you first climbed one in your grandparent’s yard, fished under one around a farm pond, or carved your initials into one in the forest.  Don’t become frustrated after a once in a lifetime storm and refuse to replant your landscape or your forest and deprive your children of those experiences.  As sage investor Warren Buffett once wisely said, “Someone is sitting in the shade today because someone planted a tree a long time ago.”

For these and other recommendations about how to “hurricane-proof” your landscape, contact your local UF/IFAS Extension Office.  Plant a tree today.

Camellia: Think Before You Limb Up

Camellia: Think Before You Limb Up

A few months ago I visited a property that had been renovated to clean up some limbs that were in danger of falling on the house.  Pruning tree limbs that are in danger of hitting a structure is always a good idea, but it’s important to look at the impacts this practice may have on the rest of a landscape.  Any time the light profile of a landscape is changed, current and future plant selection must be considered.  One often seen example occurs when trees grow to full size and shade out the lush lawn that’s underneath.  However, in this case, removal of limbs allowed more light to shine on some beautiful, old camellia bushes.

Camellia Planting and Care

Camellias do best in locations that receive filtered sunlight and are protected from the wind.  They like acidic, well-drained soils.  Trees and shrubs are generally planted 2″ to 3″ above the soil grade.  (2″ to 3″ of root ball should be exposed above the soil grade when the tree/shrub is planted.)  To help improve root oxygen exposure and help prevent a root rot situations, camellias can be planted slightly shallower than the previously stated recommendation.  For more plant establishment guidelines, please visit:  UF/IFAS Planting and Establishing Trees Guide

Scenario and Diagnosis

As mentioned above, the property in question was visited to diagnose sick camellia bushes.  Upon further inspection of the property, asking about recent changes to the landscape, and inspecting the bushes, it was clear that the camellias were receiving too much sunlight.  Sunlight damage was expressed by large brown sunscald spots on the yellowing leaves.

Sunscald on Camellia

Sunscald damage on camellia leaves. Photo Credit: Jed Dillard

The camellias had also been pruned incorrectly.  Camellias require minimal pruning.  They are normally pruned to control size or promote a tree form structure if desired.  Any pruning should be done before flower buds form in late summer.

Over Pruned Camellia

An incorrectly pruned camellia bush. Photo Credit: Jed Dillard

Solution

The best solution in this scenario was to dig up the affected camellias and move them to a location with more shade.  Sun loving shrubs were suggested as options to replace the camellia bushes.  It’s important to note that Camellia sasanqua cultivars are usually more tolerant of sunlight than Camellia japonica cultivars.  The recommendations were based on the Florida Friendly Landscaping principle of “Right Plant, Right Place”.

If you’re trying to find the right plants for you own yard, then you should check out the Florida Friendly Landscaping Interactive Plant Database.  The database gives you plant selection options for each area of your yard based on location in the state, plant type, and soil and light conditions.

How Did I Get Rust On My Blueberries?

Normally we think of rust as something that deteriorates metal, but a number of different fungal rusts can affect plants in the garden.  Rust disease can affect corn plants, cedar trees, and even blueberry bushes.  Just like the broad range of plant species that can be plagued by rust, there are a number of species of rust fungal spores floating around and ready to infest your garden.  This article will focus on leaf rust of blueberry.

Blueberry rust on top of a leaf.

Blueberry leaf rust on the top of a leaf. Photo Credit: Philip Harmon, University of Florida/IFAS Extension.

Leaf rust of blueberry in Florida is caused by the fungus Pucciniastrum vaccinii.  Although the common name of the disease is “leaf rust”, the disease can also infect the stems and fruit of blueberry plants.  The disease causes small, round spots visible on the tops of leaves.  Spots will multiply and the leaves will eventually yellow and fall off.  Young stems and green fruit can also become infected as the disease progresses.  Bright orange lesions will form on stems and fruit as the thousands of microscopic spores conjoin.  The clusters of spores are easily wiped or washed off of plant material.  When spores dry out, they become airborne and can be transferred to nearby plants.

Blueberry leaf rust on fruit.

Blueberry leaf rust on fruit. Photo Credit: Philip Harmon, University of Florida/IFAS Extension

The rust fungus thrives in hot, humid, wet conditions.  A number of cultural practices can be adopted to reduce disease progression and survival.

  • Irrigation

    Disease persistence can be reduced by limiting the amount of water that contacts the plant leaves.  Water the base of plants or install drip irrigation for your bushes rather than watering from overhead.  If overhead irrigation is the only option, then water plants in the morning rather than in the evening.  This allows the leaves to dry out over the course of the day.

  • Pruning

    Removal of approximately 25% of the oldest canes in late winter before spring growth begins will stimulate the production of new canes and should result in plants with canes of different ages and will provide a good mix of vigorous branching and fruit production.  Moderate summer pruning can also improve yield and shoot growth. When pruning, cut out vigorous shoots that are growing well beyond the desired canopy height and are in the interior portion of the bush.  This will promote a more open growth habit and help with air circulation on the remaining plant material.  Some vigorous canes developing from the ground and growing on the outside of the bush can be topped to stimulate branching and flower bud formation.

  • Mulch

    Pine bark mulch helps with establishment of young plants and helps keep soil pH low in existing plantings.  A layer of aged pine bark 3 inches deep extending about 2 feet out from the plants will provide a good growing medium for surface feeder roots.  Pine straw can be used if pine bark is unavailable.  Mulch also moderates soil temperature, helps keep weeds at bay, and adds organic matter to the soil.  Make sure to keep mulch raked back about three inches away from the plant canes to provide good air circulation to the roots.

Hopefully this article has given you some tips to have a good blueberry crop for years to come.  For more information on growing blueberries in Florida, please visit the University of Florida/IFAS EDIS Publication: Blueberry Gardener’s Guide.