Davey Tree Flipbooks

20 THE DAVEY BULLETIN | July/August 2022 EXPERTISE WEST DENVER OFFICE HELPS DOMESTIC VIOLENCE SHELTER Colorado Arborists and Lawn Care Professionals (CALCP) supports the professionalism of Colorado's tree and lawn care industry through educational opportunities, research support, and legislative advocacy. CALCP organized a day of service to improve the landscape at a Gateway Domestic Violence shelter in the Denver area as part of this work. Chris Martin, assistant district manager, West Denver office, is a board member of CALCP, and volunteered at the event. "We trimmed two honey locust trees in the yard that had a lot of dead branches that had been hitting the roof, chimney, GALL-FORMING WASPS DEVASTATE PIN OAKS AT GRANT'S FARM Home to the world-famous Budweiser Clydesdales, Grant's Farm is a refuge to more than 900 animals, including buffalo, deer, elephants, elk, goats, yaks, and more. Located in St. Louis, Missouri, this historic landmark sits on 273 acres. Tom Beshoar, district manager, St. Louis office, said there's been a problem with oak galls in the St. Louis area for the last six years or so, and this year it's become worse. He noticed many of the pin oak trees at Grant's Farm were plagued with oak galls. Beshoar connected with Adam Baker, technical advisor, Davey Institute, and Arborjet's Emmett Muennink, south central technical manager, to come up with a treatment plan to try to save the oaks. "All of these pin oaks are going to die if we don't try to do something. While we don't know if the treatments are going to work, it is better to try to do something rather than nothing," Beshoar said. They began a three-year study on 40 mature pin oak trees on Grant's Farm in April. The pin oaks are being treated in three ways, with fertilization and watering; injecting TREE-äge ® R10; and a combination of the two. The oak galls are formed by female oak gall wasps inserting eggs into the oaks' branches, causing the areas to swell, which is a three-year generation cycle. There is also a yearly sexual reproduction cycle, which forms galls on the leaves. "It takes about 33 months before the wasp emerges. We need to track it for about three years to see if we're getting any success, going back once a year to assess the amount of new gall formation on the trees in response to our treat- ments," Baker said. There are conflicting opinions on how to control the wasps. "One of the big benefits from this is at the end of the day this study will lead to a science-backed recommendation from Davey," Baker said. Oak galls fill the branches of a mature pin oak on Grant's Farm. Visitors can tour the farm via an open- air tour van. Highlights of Grant's Farm include Ulysses S. Grant's log cabin, the Busch Family Estate home, and the opportunity to hand-feed a variety of animals, as well as an Animal Encounters walking tour. STEWARDSHIP Colorado Arborists and Lawn Care Professionals members cared for a yard at a Gateway Domestic Violence shelter by providing lawn fertilization, putting down mulch beds, and working on the sprinklers. Pictured, from left, from the West Denver office are trimmer Bryce Evans, Ryan Pinto, foreman, Chris Martin, assistant district manager, and Anthony Difronzo, trimmer. and phone lines. Small children play in the yard, so it was really nice to get the trees cleaned up for them," Martin said. "My team enjoyed being able to make a difference in the community as well." Inset: An up-close look at an oak gall. A gall wasp (circled) is on the left.

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