July-August 2009 Volume 3, Issue 4 Getting The Black Out Of 1 Roses What Is This Alien Stuff 2 On My Plants' Bark Do Something Wild In 3 Your Backyard! Common Summer Tree 4 Problems Orchard Orb-Weaver 4 Spider FAQ's: Crape Myrtles, 5 the Lilac Of The South Wisteria Gone Wild 6 Fall Vegetable Gardening 7 Is Right Around The Corner Solving Fruit Tree 8 Problems Upcoming Events 9 Black spot will cause a general weakening of the plant so that progressively fewer and fewer blooms are formed if the disease is left unchecked. Photo Credits: Theresa Friday, Santa Rosa County Getting The Black Out Of Roses One of the biggest problems fa- cing homeowners who grow roses is black spot. This fungal disease can reduce the quality and life ex- pectancy of a rose plant. Roses can also have poor performance from other factors such as root stocks and scions that are not suitable for Florida, under watering and under fertilization. Symptoms of this disease appear as black spots on the upper sur- face of the leaf. Yellowing around the spots on infected leaves also occurs. Leaf defoliation can be severe on some cultivars of roses. Spores from the previous season are spread by rain or overhead ir- rigation. The spores must be wet for several hours to infect plant tis- sues. Therefore, it is important to water early in the morning to al- low the plant to dry off quickly as the sun rises. Drip irrigation is a Volume 3, Issue 4 July-August 2009 1
Transcript
July-August 2009Volume 3, Issue 4
Getting The Black Out Of 1RosesWhat Is This Alien Stuff 2On My Plants' BarkDo Something Wild In 3Your Backyard!Common Summer Tree 4ProblemsOrchard Orb-Weaver 4SpiderFAQ's: Crape Myrtles, 5the Lilac Of The SouthWisteria Gone Wild 6Fall Vegetable Gardening 7Is Right Around TheCornerSolving Fruit Tree 8ProblemsUpcoming Events 9
Black spot will cause a general weakening of the plant sothat progressively fewer and fewer blooms are formed if thedisease is left unchecked.
Photo Credits: Theresa Friday, Santa Rosa County
Getting The Black OutOf Roses
One of the biggest problems fa-cing homeowners who grow rosesis black spot. This fungal diseasecan reduce the quality and life ex-pectancy of a rose plant. Roses canalso have poor performance fromother factors such as root stocksand scions that are not suitable forFlorida, under watering and underfertilization.
Symptoms of this disease appearas black spots on the upper sur-face of the leaf. Yellowing aroundthe spots on infected leaves alsooccurs. Leaf defoliation can besevere on some cultivars of roses.
Spores from the previous seasonare spread by rain or overhead ir-rigation. The spores must be wetfor several hours to infect plant tis-sues. Therefore, it is important towater early in the morning to al-low the plant to dry off quickly asthe sun rises. Drip irrigation is a
Volume 3, Issue 4 July-August 2009 1
good way to keep water off leaves and canes.
It takes three to 16 days for the symptoms to appear afterinfection. The optimum temperature for disease develop-ment is 64°F. Spore germination occurs from 59 to81°F. With such a wide temperature range, this diseasecan continue to develop as long as the moisture is avail-able during the season.
Cultural practices such as planting resistant cultivars, re-moving and disposing of fallen leaves, pruning of caneslate in the winter before new shoots are produced andproper irrigation will reduce the chances of black spot.
When using chemical control, apply a protectant fungi-cide at bud break and bimonthly until leaves are com-pletely expanded. During the summer, fungicide applica-tions every 7-14 days may be necessary to manage thedisease.
Fungicides labeled for the control of black spot of rosesinclude: captan, chlorothalonil (Ferti-lome® Liquid fun-gicide, Bonide® Fungonil Multipurpose Fungicide, Or-tho Garden Disease Control), copper sulfate, mancozeb,sulfur, neem oil, thiophanate-methyl (Ferti-lome® HaltSystemic Fungicide, Green Light® Systemic Fungicide)and triforine (Ortho® Rose Pride Rose & Shrub DiseaseControl). To reduce fungicide resistance, rotate amongproducts with different modes of action.
Source: Jozer Mangandi, graduate student, Departmentof Environmental Horticulture; Natalia A. Peres, assist-ant professor, Department of Plant Pathology, GulfCoast Research and Education Center (REC)--Balm;Florida Cooperative Extension Service, Institute of Foodand Agricultural Sciences, Document PP268.
Throughout the year I get many calls asking "what is thismossy-like stuff growing on my landscape plant's bark?"For the most part the calls are in the spring time whenpeople have come out of hibernation from the winter andsee their landscape plants covered with alien-lookinggrowth. Well I am here to say it is not alien, though itmay look like it is. These are lichens.
Lichens often get mistaken for some unusual fungus thatis killing their trees. However lichens are not single or-ganisms, but rather a combination of two organisms thatlive together in a beneficial way. There are over 20,000different types of lichens found in nature. Lichens con-sist of a fungus and cannot survive on its own; therefore,the fungus is more dependent upon its algae partnerwhich produces enough food for both to survive.Lichens are also very different from plants because theycan survive a complete loss of water. During this time,brittle pieces that flake off can later grow into newlichens. When moisture becomes available again, thelichen absorbs water and returns to their fleshy form. Sowith this stated, the lichens growing on trees and shrubsare not parasites and do not harm the plants in any way.Lichens use plants as support structures to become estab-lished.
Lichens on Bradford pear tree bark
Photo Credits: Eddie Powell
There are four different forms of lichens found, crustose
(crust-like, growing tight against the substrate), squamu-lose (tightly clustered and slightly flattened pebble-likeunits), foliose (leaf like, with flat sheets of tissue nottightly bound), and fruticose (free-standing branchingtubes). Colors range from white to gray, green, red, yel-low, and black. Lichens commonly found in our area arein the crustose, foliose, or fruticose form, and are white,gray, or gray-green in color.
Because lichens produce chemicals, they have very fewnatural predators. However, the most serious threat tolichens is air pollution. Most lichens will not grow in apolluted atmosphere and therefore you should be glad tosee lichen here or there in your yard, as this is an indica-tion that the air is relatively clean.
Are you a wildlife enthusiast? With over 1,200 types ofanimals in Florida, the odds are you have creatures liv-ing in your backyard besides pets. The Florida Back-yard Landscapes for Wildlife Program is designed forhomeowners interested in creating more backyard wild-life habitat. Participants in the program complete an ap-plication listing specific actions taken to attract animals,such as planting food sources or providing houses orcover, along with the types of animals typically ob-served. The application also includes a rough sketch ofthe landscape design showing locations of feeders, nec-tar plants, water sources, and other features. Once ap-proved, individuals can have their yards certified as anofficial wildlife habitat from IFAS Extension, and re-ceive a certificate and a yard sign stating, “I didsomething WILD in my yard!”
At any point, participants can request information fromtheir local horticulture or natural resources ExtensionAgent on the best way to design and maintain wildlifehabitat. For an application, contact your local Exten-sion Office or visit the Wildlife Extension website athttp://www.wec.ufl.edu/extension/landscaping/fblw/ for
more information.
Gopher tortoises are on the Florida endangered specieslist, and are typically found in upland pine flatwoods orcoastal dunes. Their large burrows also provide habitatfor other animals.
Photo Credits: Carrie T. Stevenson, Brooker Creek
Nature Preserve--2009
For bird lovers, the Florida Public Bird Watching Pro-gram may be of interest. This program allows parti-cipants to enter bird survey data on a public website,helping homeowners and researchers keep track of mi-grating and resident species throughout the year. The in-formation can help property owners attract particularspecies and create more ecologically sound landscapes.Bird surveys may be submitted from anywhere in thestate, including parks, yards or neighborhood commonareas. For more information, visithttp://bird.ifas.ufl.edu.
Carrie T. StevensonFlorida Yards & Neighborhoods Agent
It is that time of year again when I begin getting an over-whelming amount of calls on tree problems. Many in-sect and disease problems have had sufficient time to de-velop and damage a tree. Non biological stresses suchas lightning, drought and heat stresses also haveweakened some trees. During the summer, temperaturesare high and the physiological process of trees such astranspiration and respiration are running at peak rates.So if any part of a tree (roots, etc.) is compromised, thetree quickly can become overwhelmed and begin to de-cline. Over time, this decline can get to the point wherewe see visible signs that we can recognize. These vis-ible signs may include changing leaf color, leaves turn-ing brown, loss of leaves, visible lightning strikes or sap(often being discolored) oozing from a tree.
Once these signs show themselves sometimes it may beto late too do anything. Often, especially when leavesonly turn partially brown or are eaten by an insect, thedamage is only temporary if the tree is not under addi-tional stresses like being a newly planted tree.
Other times, the thing to do is remove the tree to helpprevent the spread of this problem to other trees. This isoften the case when pine beetles are discovered in a tree.Trees that are already turning brown are just breedingareas for more beetles. If this is happening, adjacent pinetrees will be at risk. Then you are likely to have moretrees to remove in the long run.
If it is an insect consuming leaves, such as a caterpillar,and the tree is not under stress I often recommend to justlet nature take its course. Probably something else likebirds will consume the caterpillars or their adult butter-flies and moths. This then helps adults raise their babies,as birds are often looking for high protein sources likeinsects to feed to them this time of year.
Diagnosing a tree problem and finding a cure is not al-ways easy. Generally the best thing to do to keep treeshealthy is to have a good mulch bed underneath theircrown so the soil is protected and the nutrients that are inleaves and seeds, etc. are recycled. Also, growing treesin groups with proper spacing allows trees to have pro-tection from each other but minimizes competitionbetween them. Trees in this situation are often less
stressed and thus less likely to succumb to insect anddisease problems.
In many aspects of our lives, the color red often puts usat attention. This is true in relation to insects and spidersas well. When we see red markings on garden creatures,we know to be cautious. Some of the most commonlyrecognized spiders with red markings are the widows. Itis important to learn to recognize widows because we dohave them in our area; however, not all spiders with redmarkings on their body are poisonous to people.
The orchard orb-weaver is just one of our many orbweaver spiders that help manage insects in a landscape.
One very common spider found in most every garden isthe orchard orb-weaver. It is a small spider with an ab-domen longer than wide. There are two red orange tri-angles on the underside of the abdomen (not an hour-glass) and often red spots on the upperside of the abdo-men. These spiders may also have green, yellow, andwhite markings on their bodies. The spider builds smallspiral orb webs often situated among the branches ofshrubs. The web is usually slanted instead of beingstraight up and down in the shrubs. Females hang in thewebs waiting for an insect meal. Widow webs tend to beirregular without any circular patterns. Most widows arefound in less open areas.
Without question, the crape myrtle is the premier sum-mer flowering tree along the Gulf Coast. All cultivarsprefer full sun, good air movement and well drained soil.Even when planted in the "right place," crape myrtlesmay develop problems.
My crape myrtle is reluctant to bloom. What’swrong?
Crape myrtles flower most heavily in full, uninterruptedsunlight. Plants that have become shaded by a nearbytree will gradually reduce their bloom output. Anotherreason may be frequent irrigation and overfertilization.These practices promote vegetative growth at the ex-pense of flowering. Also, in extreme drought condi-tions flowering may be delayed. The bottom line is thatcrape myrtles bloom when they are happy. Given theproper environment and good cultural practices, yourplants should bloom normally.
The leaves of my crape myrtles are covered with yel-lowish-green insects. Many leaves have developedyellow spots and there is black, sticky substance onthe leaves.What should I do?
It sounds like you have an infestation of a sucking in-sect, probably the crape myrtle aphid. Aphids feed onplant juices and excrete a sticky substance known ashoneydew. The honeydew falls on the leaves belowthem and frequently a black mildew, called sooty mold,grows on the honeydew.
Typically, if the crape myrtle is large and healthy, treat-ment may not be necessary. However, if you are seeingsignificant damage, you may need to control the aphids.In north Florida, crape myrtle aphid populations gener-ally peak between late June and early August. There-fore, control measures should begin by the first week ofJuly.
The larvae of a lady beetle (the larger insect) will feed onlarge quantities of crape myrtle aphids (the smaller in-sect) and provide natural control when aphid numbersare low.
Photo Credits: Theresa Friday, Santa Rosa County
Extension
The least toxic chemical controls include insecticidalsoap or horticultural oil. Be sure to follow the label dir-ections. Because aphids reproduce so quickly, repeatedapplications may be necessary. For other options, referto the UF/IFAS publication, Insect Management onLandscape Plants, at http://edis.ifas.ufl.edu/IG013.
One thing to consider is that aphids are food for many ofour area's beneficial insects. Read more about this amaz-ing interaction at http://edis.ifas.ufl.edu/IN663, aUF/IFAS publication on the Crapemyrtle Aphid.
This is absolutely and totally a normal occurrence.Many crape myrtles have exfoliating bark. It peels off inlong hunks, often exposing glossy, honey-color trunks.Some cultivars, such as Natchez, have beautiful cinna-mon-colored bark. In all cases, the peeling bark is com-pletely harmless.
I have sprouts coming up around my crape myrtletree. How can I stop them? Can I transplant them?
Crape myrtles generally require little pruning. However,"suckers" or water sprouts may develop along the lowerportions of main stems or from roots. These should beremoved when using crape myrtles as trees.
Photo Credits: Theresa Friday, Santa Rosa County
Extension
Crape myrtles, like yaupon hollies, will throw out rootsprouts. Left in place, they will create a thicket of crapemyrtle plants. Assuming you do not want that, youshould dig and remove them using a sharp spade. Theentire process probably won't take more than a fewminutes each year. You cannot spray them, since theyare tethered to the mother plant. Since crape myrtles are
propagated by cuttings, their root systems are the sameas the top growth, so these sprouts can be used as ameans of staring new and identical plants.
Q. We planted Wisteria for its beautiful spring flowersand it grew and grew and took over everything. Nowwe’re trying to get rid of it. New plants are sproutingeverywhere - up to ten feet away from the original plant.Is there a way to rid our landscape of this now wildplant?
A. Chinese Wisteria, Wisteria sinensis, can be a bigproblem to control. I've seen entire fields taken over byit. Yet, many people wonder why you would want to killa beautiful plant like Wisteria. It's possible to keep it inbounds for a while (possibly years) in the middle of alawn with its new shoots arising from roots beingroutinely mowed. But in many cases, given enough time,shoots coming from roots will escape and then begin totake over - growing on adjacent property, climbing trees,etc.
In order to control an established vine, you must be per-sistent. Your best bet, outside of moving, is to use a "cutstump" treatment on the main plant and every shoot thatsprouts. Use an herbicide that contains triclopyr. Somebrand names include Enforcer Brush Killer, OrthoBrush-B-Gon, Ferti-lome Brush Killer-Stump Killer,Garlon (forestry use) and Remedy (farm use). Cut themain stem (trunk) as close to the ground as possible andas level as possible to facilitate application of the herbi-cide to prevent sprouting. It is critical to immediately ap-ply the product to the freshly cut "stump." Stumps thatare not treated with the herbicide will sprout. Alwaysfollow label directions and precautions and be very care-ful to not get the product on adjacent desirable plants, in-cluding their roots.
Other invasive, undesirable woody plants can be con-trolled using this method such as Chinese tallow (pop-corn tree), Chinese privet (Ligustrum sinensis) and Ja-panese honeysuckle (Lonicera japonica).
Application of triclopyr herbicide to cut stump
Photo Credits: Larry Williams & Sheila Dunning,
Okaloosa County Extension Agents
Larry L WilliamsResidential Horticulture Extension Agent
Fall Vegetable Gardening Is RightAround The Corner
With the outside temps and the humidity into the 90’snow, you may not think about fall gardening at all. Thereseems to be a renewed interest in vegetable gardeningand fall is a great time for growing vegetables, espe-cially our greens and leafy ones. It is not too early toplan for it, especially if this is the first time you havetried to do a garden in the fall.
First, make a plan to plant what you and your family liketo prepare and eat. Write down the names of the veget-ables and allocate space for each by what they grow in(rows or beds). If you are preparing raised beds for thefirst time, or in a new garden spot, take a soil sample andsend it to a reputable lab. University labs, such as theUniversity of Florida, have the expertise and internalquality controls to give recommendations on garden andother crops and lawns. Pull your samples soon and beable to apply any recommended lime or fertilizers in atimely manner. Lime usually takes 2-3 months to dis-solve and become available to the plants. Be sure to ro-
tate root crops such as carrots and potatoes to new areasevery third year to avoid nematode and fruit qualityproblems.
Practice field sanitation—remove all summer grownplants first. Clear a strip around the garden at least sixfeet wide so that thrips, whiteflies and aphids will nothave instant or immediate access to your fresh, green ve-getables. Weed control in strips will help cut down onhost plants for these insects.
Plant or transplant resistant varieties of the cool seasoncrops when they are available. Check with your Exten-sion Agent for a list of disease resistant hybrids that areoffered to the homeowner. Mosaic viruses and spottedwilt viruses have no chemical cures presently. Somebeans, snow peas, and English peas are resistant to cer-tain diseases, but will need to be monitored for fungiafter leaves form. Use fungicide treated seed to help en-sure a good stand. Some yellow crooknecks and straight-necks squashes, such as Prelude and Multi-Pik, are res-istant to mosaic viruses, but will still need insecticides tocontrol the rindworms, cucumber beetles, and others thatmay attack the stalks and young fruits.
Charles L . BrasherCourtesy Extension Agent-FAMU/Vegetables
There are several insects that may cause problems forfruits. Some of these insects target the leaves while oth-ers target the flowers or fruits. Some common insectsthat may attack fruit trees include thrips, weevils, aphids,spider mites, caterpillars, stinkbugs, leaf footed bugs,plant bugs, sap bugs, and borers. Thrips and someweevils attack the blooms. Aphids, spider mites, cater-pillar, and beetles will most often cause damage to thefoliage. Stinkbugs, plant bugs, leaf footed bugs,weevils, and sap bugs are usually problems on the fruit.When it comes to insect management, chemical controlis the most effective means of reducing populations anddamage. Some common insecticides labeled for fruitsare listed below.
Fruit trees can also be infected by several plant diseases.These pathogens may include anthracnose, rosette, or-ange rust, leaf spot, and numerous viruses. These dis-eases can severely limit fruit production. To preventmany of these diseases, fungicides like azoxystorbin(Quadris or Amistar), chlorothalonil (Bravo), mancozeb(Dithane & Manzate), and thiophanate methyl(Topsin)may be applied along with sanitation by proper weedand insect control and planting resistant cultivars. Unfor-tunately, there is no cure for viruses--only prevention.Some common fungicides labeled for fruits are listed be-low.
Thiophanate methyl (Topsin) - Anthracnose, botrytis,powdery mildew and leaf spots
When applying pesticides, make sure that the pesti-cide is labeled for the desired crop and remember toalways read and follow pesticide labels exactly toavoid unnecessary crop injury!!!
July 7: Panhandle Butterfly House Docent Training.Learn about butterflies and become a volunteer at thisbeautiful butterfly exhibit. Training will start at 2pmCST and be held at the Welcome Center in NavarrePark. Register online by leaving an email [email protected] or call 850-434-5769 for more information.
August 1: Wildlife Expo at the University ofFlorida/PJC Milton Campus. For more information, vis-it miltongators.com or call Robin Vickers at 850-983-5216 ext. 113.
Washington County Events
July 10: Crape Myrtle Variety Workshop at NWNNursery in Chipley. For more information contact Col-lin W. Adcock at 850-638-6180.
Jackson County Events
October 10: Jackson County Master Gardeners BulbWorkshop and Sale. 10:00 AM-1:00 PM. JacksonCounty Extension Office, 2741 Pennsylvania Ave,Room “B” on the North End of the Building. Programwill consist of Dr. Gary Knox speaking on bulbs andother plants for this area, and Mrs. Linda Van Beckspeaking on daffodils and other bulbs she is an experton. Her book, “Daffodils in Florida” will be available forsale. For more information, contact the Jackson CountyMaster Gardeners at or 850-482-9620.
Jefferson County275 North Mulberry StreetMonticello, FL 32344-2249(850) 342-0187http://jefferson.ifas.ufl.edu
Walton County732 N 9 Street Ste BDeFuniak Springs, FL 32433-3804(850) 892-8172http://walton.ifas.ufl.edu
Franklin County66 Fourth StreetApalachicola, FL 32320-1775(850) 653-9337http://franklin.ifas.ufl.edu
Leon County615 Paul Russell RoadTallahassee, FL 32301-7060(850) 606-5200http://leon.ifas.ufl.edu
Washington County1424 Jackson Avenue Ste AChipley, FL 32428-1602(850) 638-6180http://washington.ifas.ufl.edu
Gadsden County2140 West Jefferson StreetQuincy, FL 32351-1905(850) 875-7255http://gadsden.ifas.ufl.edu
Liberty County10405 NW Theo Jacobs WayBristol, FL 32321-0368(850) 643-2229http://liberty.ifas.ufl.edu
Gulf County200 North 2nd StreetWewahitchka, Fl 32465-0250(850) 639-3200http://gulf.ifas.ufl.edu
Santa Rosa County6263 Dogwood DriveMilton, FL 32570-3500(850) 623-3868http://santarosa.ifas.ufl.edu
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research,educational information, and other services only to individuals and institutions that function with non-discrimination withrespect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions,or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, FloridaA&MUniversity Cooperative Extension Program, and Boards of County Commissioners Cooperating.
