FOR RELEASE: 9 February 2003
 Daniel F. Culbert,  County Extension Director

                                                               WHAT'S HOT IN FLORIDA YARDS

 Last weekend at Gardenfest I was asked to make a presentation on current issues in our local Florida yards.  Master Gardener Alan Morton reviewed the kinds of questions that have been presented to our office over the last year.  Today's column is part one of a summary of what he found, plus a few personal observations of what's Hot in our Florida Yards. 

 Cold Damage
 What's hot in our local landscapes is not a matter of the hot, but is a result of the "not".  Late last month, most of our area was
briefly visited by Jack Frost on the heels of howling Siberian Express winds.  It's taken a couple of weeks, but tender tropicals and that succulent growth is now tinged with brown.  In my travels around the county, cold damage appears to be based on location rather than the kind of plant involved.  To paraphrase our friends in real estate, recently cold damaged plants have been hurt by three things, location, location, location. 

 Tender plants in areas open to the north west are showing leaf damage.  I've got a narrow fenced in yard looking northwest.   A blue porterweed at the corner of my house felt funneled high winds, and the leaves turned brown within three days.  Some Firebush plants in front of McKee Botanical Gardens were faced with wind barreling down US 1; the leaves and stems of are now brown.

 The gut reaction is to immediately remove the cold damaged leaves and stems, pile on the fertilizers, douse it with water, and get it green again.  This may be the worst thing to do at this time. Such practices do encourage green new growth, but there is still a chance until late February that more cold temperatures could arrive. This tender young growth could all be nipped off again, and put the health of the plant in serious jeopardy.

 Do pay attention to watering needs, but lay off the fertilizer a bit longer.  The breaking buds will tell you when the plant is ready to resume growth, and will define where the living tissue remains, giving you instructions on where pruning can be done.  Always prune into green, living wood, as dead wood will not grow over the dead plant parts.

 I've put up an  Internet page on our county Extension website that refers to cold recovery references from the University of Florida.  To summarize it all, let me again modify another famous saying - this one came from John Paul Jones:  "Don't prune those plants until you see the green of their buds!"

 URBAN FOREST THREATS

 According to the kinds of calls and visits we get at our Extension office, the most  requested kind of information at our office is concerning trees.  And followed by a close second  has been shrub questions.

 We have some tree issues in our community.  Our dominant landscape trees are two kinds of oaks and the Slash Pine.   Many Slash Pines appear to be declining from our urban forest, often as a result of issues related to residential development.  When grown in natural areas, our pines do just fine.  But run over their roots with a bulldozer, reduce the root zone with trenches or canals, cover the roots with fill, and then add constant irrigation with an occasional dose of pesticides or fertilizers - it is often more than they can handle. 

 Pine trees can put up a valiant battle for a while, but they can only take it for so long.  Then our office gets the call, often several years later, when the needles turn yellow or the decomposing pine bark beetles are noticed, with an urgent plea to please save my tree.

 Our Laurel oaks are also a major part of our urban forest. Laurel oaks are the ones that are all turning yellow right now, and will lose all of their leaves in the next week or two.  Yes, Virginia, there are deciduous trees in Florida. As the leaves drop, be sure to take advantage of a very precious resource: leaf litter makes great mulch, and if you are patient, it's even better as compost.

 With the Laurel oaks being bare, we get calls this time of year on what the homeowner now sees: bright green circular branches high in the canopy of the tree.  This is mistletoe, an unusual plant not because of its Christmas lore, but because it is a parasite.  Trimming it out may improve the health of a young tree, but severe infestations in old trees may not be a cost effective alternative.

 And all of that moss - "certainly it is killing my tree".  Nope, these are epiphytes - air plants - that take up space.  We notice them more when  trees that have thin canopies, thin because of other issues, not because of the air plants.  Their only danger might be in harboring itchy chiggers, a problem only to those that remove moss from trees.

 Notice any old trees being taken out recently?  We lost a big one down at ORCA park on Oslo road recently.  Many of the Laurel oaks in our community were planted after WW2.  Guess what - Laurel oaks typically live about 50 to 60 years, under ideal conditions.  So, despite our best efforts, many of these "ancient oaks" are losing their battle with father time, not because of other issues.  The best defense is to have an on-going tree planting program that is slowly but constantly keeping the average age of our urban forest lower that the terminal age of our dominant shade trees.  I'd like to commend the Vero Beach and Sebastian Tree commissions for making great strides in this direction.

 And remember all those "development issues" I just covered with the pine trees?  They also apply to the Laurel oaks.  They are a major tree species found among the many new housing starts that are springing up in our area.  

 Another recent oak tree issue is a disease called hypoxylon canker.  Once infected, the tree will soon die.  While the conditions that encourage infection are unclear, it is thought that extremes in drought or flooding encourage this incurable fungal infection.  Look for a long strip of bark that suddenly dies and sluffs off the tree as a sign. There is little we can do but try to eliminate environmental stress to battle this issue.

 So what about Live oaks?  They are the real soldiers of our urban forest.  If properly cared for, they can live for hundreds of years.  If abused by topping, excessive irrigation of the flower beds planted next to their trunk, or if Roundup(tm) is used to kill the oak tree suckers growing from the ground, they will not live very long. Live oaks lose their leaves at this time of year too - just not all of them - and there is an opportunity to take a good look at any structural deficiencies.   If you see a "V" shaped crotch or if limbs are crossing each other, or if there are dead branches, consider asking for some assistance from a certified arborist, who has the professional training and equipment to do the job safely and correctly.  Bumps on the leaves may be galls; they are not damaging to trees and there are no labeled insecticides that can be used to eliminate them.

 TRIM SHRUBS AT RIGHT TIME

 Many of our shrub questions at this time of year deal with the how and when to prune shrubs.  It's hard to make generalizations, but here's my two cents. Pruning needs to be done with a purpose. Realize that it encourages new growth - which you may not want to do quite yet.  It is too often used to "head back" long or tall branches to control shape or height.  Better plant selection or placement could also accomplish this kind of pruning.  "Thinning out" is another pruning technique, where larger branches are removed because they are dead, or to get light into the center of the plant  - this will improve air circulation and encourage new growth.  Then there are the special exceptions, such as pruning the seasonally flowering shrubs after they have flowered.   For example, prune Gardenias in late spring to summer, but prune crepe myrtles in the fall. 

 If there's lots of older shrubs in your landscape that have been planted too close to the foundation, that have been over-pruned into unnatural boxes, or have been irrigated every day whether it was needed or not, consider replacement.   Local nurseries have a lot of new and exciting plants that would do well for replacement.   Just be sure to ask about their site requirements, including size, light, moisture, and so on.  Try to guard against the impulse plant purchase; make sure that you have a place in your Florida Yard where it will be happy.  Our Master Gardeners can help you learn about these site requirements. 

 Another big cluster of questions we field at the Extension office deals with palms.  Palms are neat - it's what makes Florida Florida, right?  The number one question we have fielded over the past year in our office is this: how do I get rid of this white crud on my sago palm?

 First off, the sagos are not palms, they're cycads.  But since they behave and are maintained in the landscape like palms, we can overlook this.  What we can't overlook is a new exotic insect pest that has appeared in our area dunging the past year.  The fancy name is aulacapsis scale, which is why we refer to it as "sago scale".  The bottom line is, if you have a sago, you have to look for this crud; if you are not looking for it, you probably have it; and if you are not treating for it, you will lose your sagos.  

 I usually suggest that scale insects can be managed with the use of insecticidal soaps or horticultural oils.  They are softer on the beneficial bugs in your Florida Yard.  But these biorational approaches will not work with this creeping crud.  If the sago infestation is heavy, a severe pruning to remove much of the infested foliage is probably a good idea, as you will need to spray not only the remaining fronds but the trunk and crown as well.  University of Florida researchers have found that the repeated use of a systemic insecticide such as Merit(tm) can help, and another product containing fish emulsions [Organcide(tm) ] also has shown to be helpful. 

 It will take repeated treatments and careful observation to get this under control.  Because of this invader, I really can't recommend Sagos for local landscapes any more, as the effort needed will be more than most people are willing to muster.  Consider our native Coontie in place of the smaller King sago, and consider a small true palm in place of the Queen sago.

 Part two of this presentation will appear in two weeks.  In the mean time, if you need additional information, consult our website at http://indian.ifas.ufl.edu or call or stop by our office.  For questions about Florida Yards, our office holds Master Gardener Clinic hours at the Extension office (1028 20th Place, Suite D, Vero Beach) during office hours, Wednesday morning at the North County Library in Sebastian, and the second and fourth Saturday of the month at the Environmental Learning Center. Our phone number is 770-5030, and you can email us at indian@ifas.ufl.edu.

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