When you don’t know what’s ailing your plant, ask an expert.
Many gardeners get stumped when a favorite plant of theirs comes down with a strange “something”. Many of these gardeners know about UF/IFAS Extension and call their local horticulture and agriculture agents for assistance in figuring out what’s going on. However, even these experts are often stumped by what they see. Fortunately, the agents have another layer of experts to fall back on. In addition to the resources in Gainesville, we have the Plant Disease Diagnostic Clinic, located at the North Florida Research Center in Quincy. Plant pathologists here can help determine what fungus, bacteria, virus, or viroid may be the problem.
Plant pathologists are basically plant doctors. They use all sorts of sophisticated techniques to determine what is the cause of a particular plant problem, from growing out fungal spores to examining DNA. Not only do these plant doctors tell us what the ailment is, they also provide recommended cures, or control options. They are also doing research to prevent different diseases from taking hold in our area and reduce the impact on our local growers.
Plant pathologist at work!
At a recent workshop in Quincy, we learned that plant pathology researchers are working on a fungus that affects watermelons, virus and bacteria that can wipe out a farmer’s tomato crop, and a virus that could impact our local roses. Working as a team of scientists, they study these pathogens in the lab and conduct controlled field experiments to figure out which techniques are most effective. Some of this research is leading to different methods and/or products that can help growers and gardeners alike keep their fields and landscapes healthy.
So, if your plants have problems, please contact your local Extension Office. If they don’t know the answer, then the network of scientists, including plant pathologists, in the UF/IFAS Extension family can be called on for backup to provide you with the best possible answer.
Gardeners love to share plants. My yard, like many of my gardener friends, is filled with plant gifts that were started from a cutting or division of a favorite plant. These two methods of growing new plants is fairly easy once you learn the techniques and allows gardeners a way to save a little money and grow more plants for their yard, special community projects, or even some fundraising events.
In our enthusiasm over a favorite plant, gardeners must be aware that we are not allowed to propagate certain plants from cuttings or division. Many of our ornamental plants, especially newer introductions are patented plants. These are seen as ‘premium’ plants that will hopefully be in demand by the public. The plant developer or nursery invests in the patent in hopes that the plant will become the next must have ornamental. Only businesses or individuals with authorization from the patent holder are able to asexual propagate these plants since the Plant Patent Act protects these new varieties for 20 years from the date of introduction.
So if you bought a beautiful Limelight hydrangea (Hydrangea paniculata ‘Limelight’ Plant patent #12,874) for your yard, you may not take a cutting to start a new plant, even if it is only for yourself.
If you want more than one Limelight Hydrangea, you must purchase it. Photo by Beth Bolles
When you visit the nursery, look on the plant label which will often indicate if the plant is patented. You may also look online to see if plant has a patent.
From time to time I am reminded of how little I know. Honestly, I am reminded on a daily basis. A few weeks ago someone asked me about the purple things hanging from the trees. Luckily, the person gave me some good southern directions on where I could find one of these things hanging around in Marianna. So I drove out to the site to get a better look. What I saw hanging in the tree was a three-sided, purple triangle about two feet tall and a foot wide. It looked to me like someone got a box kite stuck in a tree. Upon further research, it was determined this box kite like thing was a monitoring trap for the emerald ash borer (EAB).
A woman hanging an emerald ash borer trap in a tree. Photo Credit: Texas A&M University
The emerald ash borer (EAB) is a destructive, exotic wood-boring beetle native to Asia. It was first discovered in North America in July 2002 and has made a home in Michigan, Ohio and Ontario, Canada. Millions of ash trees have been killed by the EAB in Michigan and invested ash tree nursery stock in other states indicates the potential for increased spread of the pest. EAB has made its way to the south and has been found in Louisiana and Arkansas.
Monitoring traps are not the only means of EAB detection. A proactive approach utilizing observant citizens can help keep an eye out for potential populations. You can use these tips to monitor your community for emerald ash borers:
Ash Tree Identification – Ash trees are identified by their (1) opposite branching pattern, (2) compound leaves with 5-9 leaflets, and (3) diamond shaped bark ridges on mature trees.
A compound leaf of an ash tree. Photo Credit: FDACS
Woodpecker Damage – Of course, not all woodpecker damage on ash trees is associated with EAB infestation, but woodpecker damage in the upper part of the tree can indicate their presence. The woodpecker damage is usually accompanied by vertical cracks in the bark.
Canopy Thinning – As the attack progresses, bark cracking continues and the canopy in the upper half of the tree begins to thin.
Michigan ash tree showing decline due to Emerald ash borer. Photo Credit: USDA
Tunnels and Holes – The emerald ash borer makes distinctive S-shaped tunnels that differ from damage from other borers.
EAB Damage (left) VS Other Borer Damage (right). Photo Credit: Texas A&M University
This beetle hitchhikes on firewood and infests new areas at an alarming rate. Although the EAB has not yet been detected in Florida, transporting firewood from other states puts Florida ash trees at risk. Your help is needed to detect possible infestations so they can be quickly eradicated. The information available at the following links will help you identify the EAB, EAB host trees, and infestation symptoms.
Humans have used animal manures to fertilize food crops for thousands of years. Manures are an organic source of plant nutrients and are often a waste byproduct that must be properly managed when raising animals. Today, many farmers and backyard gardeners continue to use animal manures to provide nutrition to their crops. However, a recent experience at our local extension office brought to our attention the need to know what else, besides nutrients, is in the manure used.
A local backyard gardener brought in samples of tomato plants that had strange new growth. She had purchased the tomato plants, along with other vegetable plants, from a local nursery. When she repotted the tomato plants into larger pots, she added horse manure from her own horses to the soil mix. She then noticed this strange growth on the tomatoes, but not in the other vegetable plants that were repotted without adding horse manure. Herbicide damage was one of the first potential causes we suggested, since the new growth was twisted and distorted, a common symptom of plants that have been sprayed by herbicides. The gardener was sure she had not sprayed any herbicides near these plants, or in the pasture where she keeps her horses.
Herbicide damaged tomato plants. Photo by: Mark Tancig
Photos of the tomato plants were shared with other NW District agents and an agriculture agent with livestock and hay producer experience had the probable answer – herbicide damage due to the horses being fed hay from a hayfield that was treated with a particular herbicide. Interestingly, this agent also had experience with these symptoms after their neighbor had similar issues using manure to fertilize the garden.
Herbicides with the active ingredients picloram or aminopyralid are able to cause this kind of unexpected damage to many gardeners’ crops. Herbicides containing these active ingredients are used in hayfields to control broadleaf weeds. These herbicides are especially effective at controlling hard to manage weeds such as thistle, nightshade, and nettle. They also provide long-lasting weed control. Unfortunately, the persistence of these ingredients extends into the hay, and also persists in the manure and urine of animals who eat hay from treated fields. These ingredients pass through the animal unchanged and remain active as an herbicide. Since many vegetable crops are broadleaf plants, the herbicide’s ingredients cause injury.
So what can a farmer or backyard gardener do to prevent this problem? When purchasing hay for livestock, ask the seller if they know whether the hayfield has been treated with herbicides that contain either picloram or aminopyralid. Most herbicides are known by their common names, rather than their chemical name. If they give you a common name or brand name, the active ingredient can be obtained by contacting your local extension office. If the seller can’t tell you, then, as a precaution, do not use the manure to fertilize broadleaf vegetable crops. The same question should be asked if purchasing hay for mulch as well. Composting the manure or hay does not break down the active ingredient, and may even concentrate it.
While we continue to use animal manures to fertilize our crops as our ancestors did, it’s important to remember that many of the tools and products we use today are much more advanced. These advanced products require that we stay informed of all precautions, use them responsibly, and, in this case, inform end users of any precautions. Remember to always read and follow the label and ask questions. And if a science-based answer is what you’re looking for, your local extension office is a good place to go!
In the last few weeks, more garden pests have arrived! It is a fact of life in northwest Florida that we will have a few things in our garden including heat, moisture (humidity and rainfall), and BUGS! With a cooler spring the arrival of some of the troublesome pests in the garden seemed to be delayed a few weeks. It was nice while it lasted but the insect pests are here to stay until frost in the fall or winter (at least we hope for a frost this year).
There are thousands of insects that you can see in your garden. It’s wise to identify them before making a decision to spray an insecticide or remove them by another method. Insect samples can be taken to your local county extension office for identification.
In this article we will just discuss one of the top insect pests in the vegetable garden, caterpillars, and what you can do about them.
Mature larva of the cabbage looper. Photograph by John L. Capinera, University of Florida.
Beet armyworms, fall armyworms, hornworms, cabbage loopers, southern armyworms, tomato fruitworms, and other caterpillars love to feed on tomato foliage and fruit. They will show up eventually on tomato plants in the garden, if not this year then in the future. These larvae are immature moths and cause a lot of damage if left unchecked. The homeowner can control them effectively with Organic Materials Review Institute (OMRI) approved pesticides. A bacterial biological insecticide called Bacillusthuringiensis, also referred to as B.t., can be very effective in controlling these caterpillar pests. B.t. is a stomach toxin to these pests and will cause them to quit eating and starve to death. The key to using B.t. effectively is to routinely apply it before the caterpillars hatch from their eggs as the smaller caterpillars are easiest to control. Larger caterpillars are more difficult to control.
For more information related to using OMRI pesticides:
Coral ardisia is also known as coral berry, spice berry, and scratchthroat. It was introduced into Florida in the early 1900’s for ornamental purposes.
Coral ardisia. Photo credit: Les Harrison.
In the ensuing years it has since escaped cultivation and become established in hardwood hammocks and other moist woods of natural areas and grazing lands. Specimens have been collected from 19 western and south-central Florida counties as of 2004.
This evergreen sub-shrub reaches a height of 1.5 to six feet and tends to grow in multi-stemmed clumps. Leaves are alternate, 8 inches long, dark green above, waxy, without hairs, and have scalloped margins and calluses in the margin notches.
Flowers are typically pink to white in stalked axillary clusters, usually drooping below the foliage. The fruit is a bright red, globose, single-seeded berry, measuring approximately 0.25 inches in diameter. White-berried populations are also known to exist.
Coral ardisia is considered invasive. Control of coral ardisia may be accomplished by two methods. A low-volume foliar application of Garlon 4 or Remedy provides suppression of this plant. Complete foliar coverage is essential to success and retreatment will be necessary for complete control.
Basal bark applications with Garlon 4 or Remedy in an oil carrier can also be utilized for suppressing this invasive weed. Do not apply more than 8 quarts of Remedy or Garlon 4 per acre and treat no more than ten percent of the total grazed area if applying greater than two quarts per acre.
