by Larry Williams | Dec 17, 2013
Common symptoms of the black twig borer. Image Credit Matthew Orwat UF IFAS Extension
Q. Small branches are dying in some of my trees. What’s causing this?
A. More than likely the culprit is the Black Twig Borer. This very small beetle, about 1/16 inch long, has been active this year.
Common trees attacked include cedar, golden rain tree, maple, redbud, sweetgum, loquat, dogwood, Shumard oak, Chinese elm, magnolia, Bradford pear and pecan. The beetle is not limited to these trees. And it may attack woody shrubs and grapevines.
Black Twig Borer Entry Holes. Image Credit Matthew Orwat UF IFAS Extension
Black Twig Borer Entry Holes. White Frass Visible. Image Credit Matthew Orwat UF IFAS Extension
This beetle only damages branches that are approximately pencil size in diameter. These small branches die above the point of entrance with the leaves turning brown, creating a flagging effect of numerous dead branches scattered throughout the outer canopy of the tree. These dead twigs with their brown leaves are what bring attention to the infested trees.
Bending an infested twig downward will result in it snapping or breaking at the entrance/exit hole. Carefully putting the twig back together may allow you to see the hole. The hole is usually on the underside of the branch and will be very small, about the size of pencil lead in diameter. Sometimes you may see the minute, shiny black beetle and/or the white brood inside the hollowed out area of the twig at the point where it snapped.
Black Twig Borer inside the stem. Image Credit Matthew Orwat UF IFAS Extension
The black twig borer, Xylosandrus compactus, is one of the few ambrosia beetles that will attack healthy trees. However, the heavy rainfall this summer stressed many of our tree and plant species making them more susceptible to insect damage and disease.Female beetles bore into small branches or twigs of woody plants, excavate tunnels in the wood or pith and produce a brood. Damage occurs when the beetle introduces ambrosia fungi on which the larvae feed. The beetles emerge in late February, attack twigs in March and brood production begins in April. Highest population levels occur from June to September. Adults spend the winter in damaged twigs and branches. So it’s important to pickup and dispose of the small branches as they fall.
Where practical, the best control is to prune tree limbs 3-4 inches below the infested area, then remove and destroy the limbs. Proper mulching, avoiding over fertilization and irrigating during dry weather should improve tree health, allowing trees to better withstand attacks. Chemical controls are usually not practical or effective.
Entry point from a different angle. Image Credit Matthew Orwat UF IFAS Extension
Additional information on this beetle is available though the UF IFAS Extension Office, your County Forester or online at the UF IFAS Featured Creature page
by Beth Bolles | Nov 11, 2013
Fall color in the Florida landscape may be a little different than more northern areas but it is just as dramatic with the right plant selections. One of the favorite perennials that is in peak bloom right now is the Cassia or butterfly plant, Cassia bicapsularis. Grown for its showy bright yellow flowers, this soft-wooded perennial can be a garden accent when grown as a small tree. Plants normally grows as a multi-stemmed plant with a vase shape or rounded canopy. Size ranges from 5-10 feet in height and the best flowering is when plants receive full sun.
An added benefit of this species of cassia is that it can serve as a host for sulfur butterflies. Blooms will often last until first frost and plants may be injured by freezing temperatures. Homeowners will cut back cold damaged stems and wait for regrowth in the spring. During the growing season, larger plants may need support and summer storms can break some branches. Despite these issues, the fall flower show makes this a highlight in a garden. Learn more about this cassia from the University of Florida IFAS Extension.
by Mary Salinas | Nov 4, 2013
For centuries, people annoyed with plant pests have used oils to control insects, mites, and even some fungal diseases. Current oil products are better than ever!
Sample oil products for pest control. Photo by Mary Derrick.
Commercially available horticultural oils are mineral oils from refined petroleum products. Impurities are removed and then an emulsifying agent is added that allows the oil to mix with water for application. Neem oil is a newer product that has become increasingly popular; the oil is an extract of the seeds of the neem tree.
What are some of the advantages of using an oil for pest control?
- Oils are inexpensive and easy to apply
- Oils can be used on most plants (check the label for a list!)
- Oils control a wide range of pests that feed on plants (again, check the label for a list of pests the product will control!)
- Oils pose a low risk to people, pets, and desirable beneficial predators
- Since oils kill pests by blocking their breathing holes (spiracles) and/or gumming up their mouthparts, there is no chance for resistance to develop
- One product can control both insects and some diseases like powdery mildew at once
- Oils can be combined with some other pesticides to provide greater control
[warning] Don’t combine with, or use within 30 days of, any sulfur based pesticide. The combination can harm your plants![/warning]
There are always drawbacks to a product. What are the drawbacks?
- Some plants (including cryptomeria, junipers, cedars, maples, and redbud) are damaged by oils – check the label!
- Ensure good coverage during spraying as pests must be contacted with the oil in order for the control to work
- Oils break down quickly and reapplication may be necessary
- Check the label for instructions on the temperature range when it can be used. Older formulations generally are safe when temperatures are in the 40 to 80°F range but ultra-fine oils can generally be safely applied during hotter weather.
For further information:
Natural Products for Insect Pest Management from UF IFAS Extension
Insect Control: Horticultural Oils from Colorado State University Extension
Less Toxic Pesticides from Clemson University Cooperative Extension
by Roy Carter | Nov 4, 2013
Fertilizer Spreader on lawn. Image Credit UF IFAS Extension FYN Program
Fertilizers are manufactured from a wide variety of materials to supply plant nutrients. Once these materials are mixed, it becomes difficult to distinguish the materials present. In the past, a few unscrupulous manufacturers have taken advantage of this to increase their profit. To protect consumers and legitimate manufacturers from such practices, The Florida legislature enacted the first fertilizer law in 1889 and has amended it many times since enactment. These laws regulate the manufacture and sale of fertilizer in the state.
The law requires that the manufacturer purchase and affix a label to each bag, package, container, or lot of fertilizer offered for sale in the state. The law requires that each label show specific information about the analysis and composition of the mixture or material.
Image Credit UF IFAS
The key information comes in the guaranteed analysis section of the label. It tells the home gardener the ratio by percentage of the primary plant nutrients. The number s are in the order of these primary nutrients; Nitrogen, Phosphorus and Potassium. For example an 8-8-8 fertilizer would be eight percent nitrogen compound, eight percent phosphorus compound and eight percent potassium compound.
There’s some other information in this section of the label that may seem even more complicated but it’s also important. The label explains how much chlorine the fertilizer can contain. Chlorine can reduce the quality of some vegetable and flowers.
It informs the buyer what materials the primary plant nutrients are derived from. This can assist in determining the quality of the fertilizer.
Probably the most difficult part of the label to read, certainly the hardest part to describe, is the information listed right after the total nitrogen figure in the guaranteed analysis section. In addition the total amount of nitrogen, the label gives the amount of each of several types of nitrogen present in the fertilizer. This information will seem confusing, but it also offers a glimpse into how the fertilizer will work in specific types of soil.
Terms such as nitrate nitrogen ammoniacal nitrogen, water-soluble organic nitrogen and/or urea nitrogen can be used by plants fairly quickly. These nitrogen forms in fertilizer are great for a vegetable garden. But nitrate and water-soluble organic nitrogen are rapidly leached out of the soil so they don’t last very long. Ammoniacal and water insoluble nitrogen will stay longer in sandy soils.
Fertilizer with a high percentage of natural organic nitrogen is used by the plants slowly over a fairly long period of time. This kind of slow release fertilizer would be good for lawns helping them stay green without causing spurts of extra fast growth.
This is a complicated subject, hard to fully explain in one article. This is the take home message: almost any fertilizer purchased in Florida is a good one if it has the ingredients required for plant health and if the price is fair in terms of the total amount of plant nutrients it contains.
For more information on Florida fertilizer label contact your local UF IFAS Extension office or read this publication on the Florida Fertilizer Label.
by Matthew Orwat | Oct 21, 2013
by Gary Knox | Sep 30, 2013
The Discovery Garden, showcasing new plants, in Gardens of the Big Bend at UF/IFAS North Florida Research and Education Center, Quincy.
The University of Florida Institute of Food and Agricultural Sciences presents “Art & Garden,” Saturday October 5, at the North Florida Research and Education Center (NFREC) in Quincy. The free event will highlight creative ways to explore visual art and the art of gardening.
Spend the day learning, discovering and engaging in fun activities for the whole family. Learn about floral arranging, container gardens, native plants that attract wildlife, and combating pests and invasive plants in your garden. Join a walking tour of the Gardens or take a trolley tour to view cold-hardy citrus and deciduous fruit. Watch plein-air artists painting on-site throughout the garden. Discover how to make mosaic stepping stones as well as birdbaths from large leaves. Children can spend the day painting pumpkins, planting sweet potato sprouts to take home, or painting, drawing, and making birdfeeders with staff and volunteers from the Gadsden Arts Center.
An exciting array of trees, shrubs, flowers, organic produce and arts and crafts will be for sale. NFREC staff will be offering free soil testing and a plant disease clinic, so bring a sample of your soil or a clipping of a plant problem from your home garden. The day-long, family-friendly event is free and open to the public.
When:
Saturday, October 5, 9:00 am to 4:00 pm EDT
Where:
University of Florida/IFAS, North Florida Research and Education Center, 155 Research Road, Quincy, FL. Located just north of I-10 Exit 181, 3 miles south of Quincy, off Pat Thomas Highway, SR 267.
Who:
Presented by the University of Florida Institute of Food and Agricultural Sciences, North Florida Research and Education Center in collaboration with the Gadsden Arts Center, Gardening Friends of the Big Bend, Havana Garden Club, Quincy Garden Club, and the Tallahassee Plein-Air Artists. Sponsored in part by the Gadsden County Tourist Development Council.
Saturday’s Program:
Plant, produce and art sales by vendors
- 9:30 am Walking Tour of the Garden with Dr. Gary Knox—See new plants and capture information on your smart phone via QR codes
- 10:00 am How to Make Mosaic Stepping Stones
Wendy Adams, Havana Garden Club
Garden Pavilion
- 10:30 am Trolley Tour — Cold Hardy Citrus and Deciduous Fruits
Dr. Pete Andersen and Dr. Russ Mizell
- 11:00 am Floral Arranging Demonstration
Kay Edwards, Quincy Garden Club
Garden Pavilion
- 12:00 am Art Lecture, “Getting a Lay of the Land”
Dr. Katerie Gladdys, University of Florida School of Art
Exhibit Hall
~ First Silent Auction ends ~
- 1:00 pm How to Make and Decorate Elephant Ear Birdbaths
Cathy Boatright, Havana Garden Club
Garden Pavilion
- 1:30 pm Trolley Tour — New Plastic Mulches for Vegetable Production
Dr. Josh Freeman
- 2:00 pm How to Make a Container Garden
Dr. Gary Knox
Garden Pavilion
- 3:00 pm Walking Tour of the Garden with Dr. Gary Knox – See new plants and capture information on your smart phone via QR codes
~ Second Silent Auction ends ~
- 3:30 pm Raffle Winner Announced and Children’s Art Show Best in Show Announced
By Dawn McMillan and Gary Knox
