06/23/2021
Caplan's Tree & Landscape Consulting Newsletter, June 23, 2021
Master Gardener Garden Walk
Caplan's Tree & Landscape Consulting is a proud supporter of the 2021 SWIMGA Garden Walk, which will be held June 26-27. Purchase your tickets now at all area Schnucks Markets. For information on the Garden Walk, please check out this video: https://youtu.be/SsWgypzoTso
*****
Periodic Cicadas
The 2021 outbreak of the Brood X periodic cicada appears to be mostly over for this round. As I noticed in 2004 (the last time this brood appeared), most of emergences occurred in western Vanderburgh and eastern Posey County. Below is a list of the calls I received for this year:
• Stierley Rd., Wadesville.
• St. Joseph Ave. @ Mill Rd., Schenk Rd., Orchard Rd.
• Darmstadt Rd. & Hillsdale
• Darmstadt Rd. and Fleener Rd.
• Between Darmstadt Rd. and Old State Rd.
• Henry Lane & Bromm Rd., NW Vanderburgh Co.
• Bromm Rd. and Orchard Rd.
• Big Cynthiana Rd. (SR 65) and: Whispering Hill; Plainview Dr;
• Hogue Rd. and Marlene Dr.
• Lynnville (Warrick Co, near I-64)
• Schaeffer Rd.
• St. Wendel Rd.
• Barker & W. Virginia St.
If you are in the greater Evansville area, and had cicadas in a neighborhood not listed above, I'd appreciate it if you'd drop me a line and let me know, so I can add it to my list.
If you have not seen any periodic cicadas yet, you won't this year. If you put up netting on your trees, feel free to take it down.
Arborvitae Needle Blight
Arborvitae are one of the few evergreens that tolerate the heavy, poorly drained soil found through much of southern Indiana. While mostly problem-free, these plants often develop problems due to environmental stress, transplant shock, spider mites, deer browsing, and bagworms. However, there are some fungal diseases that can cause blighting and tip death of the needles, and we collectively call these Arborvitae Needle Blight.
Symptoms associated with needle blight include browning, death, and desiccation of the branch tips, leading to branch dieback. The picture below is a classic example of the symptoms. Infection occurs as the needles are emerging in the spring and show up at multiple sites lower in the tree canopy. Needle blight is especially serious in years with wet, rainy weather.
The fungi that cause needle blight are regarded as weak pathogens and are suspected to infect trees that are already predisposed by other forms of stress, such as improper/aggressive pruning, cold/freezing injury, water stress (drought), physical injury, and transplant shock. Disease severity typically increases as plant stress increases, so when this disease becomes apparent, it is important to also address any other problems the tree is facing to improve overall plant health and vigor. In addition, pruning out infected material will prevent further stem dieback as well as reduce inoculum for future seasons. Avoid handling/pruning the tree during wet weather as this could potentially spread fungal spores to new spots in the plant canopy.
When installing arborvitae, be sure to provide adequate plant spacing to prevent crowding and excess competition for water and root space as the tree grows. Also ensure you are picking locations that provide adequate sunlight and drainage. Chemical management is not normally needed to manage these diseases.
For more information on needle blight, including photos of the symptoms, please check out this article from Purdue: https://www.purduelandscapereport.org/article/arborvitae-needle-blight/
********
Insect Pests in the Landscape
There are several insect pests being seen now in the landscape.
Bagworms have been hatching out for a couple of weeks. The photo above shows a newly hatched bagworm, which is smaller than a dime. Although bagworms can be found on practically any plant, they are most common (and most damaging) on evergreens, especially junipers and arborvitae. They are easily controlled with Bt (sold as Dipel). Bt is a naturally occurring bacteria that only kills caterpillars, and will not harm birds, bees, or people. It is effective in the early stages of bagworm development. Once the bags reach about 1 inch in length, you need to switch to conventional insecticides, such as malathion, permethrin, or cyfluthrin. Control information can be found here:https://extension.entm.purdue.edu/publications/E-27/E-27.pdf
Japanese beetles are also out and about, after having a somewhat late start. Japanese beetles feed on over 350 species of plants, but prefer grapes, fruit trees, and roses. One of the biggest problems with controlling Japanese beetles is that they don't all emerge from the ground at the same time. So, if you treat your plants, you will still see beetles feeding days later. Avoid the temptation of spraying repeatedly, because your chemical treatment will last on the plant for at least 7 to 10 days. Information on life cycle and control can be found here:https://extension.entm.purdue.edu/publications/E-75.pdf .
********
Summer Tree Care
Summer isn’t always so kind to our trees, especially in our urban forest and landscapes. Hot, dry weather can reduce photosynthesis and food production, which in turn affects the tree's ability to shrug off insect and disease pests. Whether you have a newly planted tree or a mature shade tree, please follow these management practices:
1. Watch the water; be sure to supplement trees with additional watering when there isn’t adequate rainfall that measures at least an inch per week. Mature trees need supplemental watering just as the younger, newly established trees. Be sure to know the symptoms of dry conditions and how much to water with more information here:https://www.extension.purdue.edu/extmedia/fnr/fnr-483-w.pdf ..
2. Refresh your mulch; adding mulch to tree rings or even better, expanding them is a great way to reduce water requirements and competition for water and other resources. As trees grow, so do the roots under the tree and expanding mulching rings outward to the dripline of the crown is a great way to keep trees healthier. Also, this helps with those surface root issues as well.
3. Don’t get bugged too much; summer brings out the best in pests too! Many mite and scale species love the heat and can cause major damage and even death to your trees. Look for signs and symptoms of scale infestations and mite damage on your trees and shrubs now.
4. A nip and tuck are fine; summer is actually a good time to prune as needed to meet objectives such as reducing risk, improving branch structure, and removing conflicts or improving aesthetics. Be sure to only remove what is necessary to avoid stressing the tree. I can help with pruning your fruit and small ornamental trees.
5. Call in a professional; it is always a good idea to consult an ISA Certified Arborist for answers to tree questions. I am available to come out to your property at any time!
