Z:\charlene prickett inc. documents\mrca tree treatment update june 2007.wpd

UPDATE ON TREATMENT OF DISEASED TREES ON PRIVATE PROPERTYfrom Charlene Prickett Sadly, some Mount Royal tree lined boulevards are looking a bit ragged this summer! Most of ourmajestic elms and many ash trees are under attack from insect pests which suck the life out of them. Without treatment, many won’t survive. After wrestling with this problem for the past two years, Cityof Calgary entomologist Jim Watts is the voice of experience and the primary source of information forthis tree update. A representative from City of Calgary Urban Forestry Dept concurred entirely withWatt’s suggestions.
Pests don’t respect property lines. Though the City of Calgary has treated virtually all elm and ash treeson City property in Mt Royal, untreated trees on private property threaten our lovely boulevard treesand nearby treated private property trees with reinfection. There are two methods of tree treatment — topical application involves spraying various mixtures ofdormant (mineral) oil, soap and pesticide on affected trees. Topical treatment only kills pests oncontact. With the second method, systemic treatment, pesticide is injected directly into the tree and isdelivered throughout the tree nutritional system. Systemic pesticide kills insects feeding on bark andleaves over the period of a year or more. The systemic pesticide Confidor is again available in Calgary for commercial use due to the diligentefforts of Jim Watts who spear headed the emergency use registration of Confidor and experimentaltreatment of City owned trees over the past three seasons. Confidor has proven particularly effectiveon elm scale. It is not a threat to birds, squirrels, cats, etc.
Virtually all elms in Mount Royal suffer from some degree of scale. Those severely affected presentblackened bark as though they’ve been scorched by fire. In a desperate attempt to survive, diseasedelms try to produce leaves and small branches down the truck of the tree rather than up in the canopy. If your private property elms were injected with Confidor last summer, no further treatment is neededthis summer UNLESS your elms are in close proximity (next door or two doors away) to untreatedelms. Because the reinfection rate from nearby trees is high, it is worth your while to interface withneighbours in an effort to get all elm trees systemically treated to put the problem down for good. Timing for Confidor treatment is critical. It must be done by mid-July, but for best results, it should beinjected by July 10 (before Stampede). Only one treatment per 2-3 years may be required. It beginsto work within 48 hours, though a diseased tree may need several seasons and sufficient moisture tobounce back to good health. Although this pesticide is expected to become fully registered for useacross Canada, there could be a time gap between the expiration of Calgary’s emergency permit andtotal availability in 2008. Property owners who have not treated before, should treat diseased elmsTHIS spring.
Jim Watts is monitoring Mt Royal trees and is pleased with the state of most elms treated last summeron both private property and city owned boulevards. Elms were late leafing out this summer, but scaleis substantially reduced. Jim assures us that mature elms take several seasons to recover from theeffects of scale. While treatment can’t restore dead branches, treated elms should recover even thoughthe bark remains black this summer. It is important that recovering trees get sufficient water during thegrowing season.
Sixty-one Mt Royal residents joined a group treatment program last summer and enjoyed a reduced group price for treatment. Owners of treated elm trees should check for the following good signs. Onhot days, you should NOT see the mist of honeydew falling from the tree canopy. Patios, decks, lawnfurniture, rock walls under the tree canopy should NO longer be sticky with honeydew. If you havepressure washed these areas, the dark colouration from falling honeydew should NOT reappear. Ifyour treated elms are not at risk to reinfection from nearby untreated trees, your only chore is to keepthem well watered this summer and fall. Water under the entire tree canopy regularly, right until freezeup. Deadwood should not be pruned off until November at the earliest. You should NOT see moredeadwood appear! The outlook for Manchurian and black ash trees is less optimistic. Ash trees affected by psyllid presentdistorted leaves which “cauliflower up” with little bumps. Like elm scale, these pests can kill a tree injust a few seasons and can reinfect neighbouring trees by riding the wind. Last summer, the City ofCalgary completed Confidor treatment of most Manchurian and black ash trees on Mount Royalboulevards and parks, but Confidor treatment of ash trees was much less successful than for elms. Forunknown reasons, ash trees, particularly mature trees, do not uptake the pesticide throughout the treesystem as thoroughly as elms. Alas, Calgary has lost many ash trees. Jim estimates that systemictreatment may have saved only 25% of the ash inventory.
Jim suggests that untreated black and Manchurian ash should treated topically as soon as possible witha spray solution of soap and 0.5% Permethrin, a pesticide approved by Health Canada. Ash treestreated with Confidor injections last summer should NOT be injected again this summer. Since thesystemic Confidor injections require drilling small holes in the tree trunk, the repeat of that stress on adiseased tree two years in a row is unwise, especially since this treatment has limited success on ashtrees. If psyllid has reappeared on Confidotreated trees, Jim suggests they now be sprayed with thesoap / Permethrin solution.
Last year ArborCare was the only local tree service offering Confidor treatment. This year there are afew other companies offering the service as well. ArborCare has again offered a group rate to MtRoyal residents, and the price is better than last summer. The cost of treatment includes a servicecharge of $65 (down from $85 last summer) which includes the pesticide application of one tree plusthe cost of the Confidor at $3.75 per inch of the diameter of the tree. Treatment of additional trees onthe same property cost $20 per tree over 6 inches in diameter and $10 per smaller tree. Chemicalcosts for additional trees are calculated as above.
Group rate spraying (soap,0.5% Permethrin mix) for ash trees is $85 service charge which includes thefirst tree. Spraying of additional ash trees on the same property cost $20 per tree over 6 inches indiameter and $10 per smaller tree.
Properties which require treatment for both ash and elms will be charged one service charge of $65which will include one tree. Additional trees are priced at rates shown above.
ArborCare treats three or more properties in the same trip to our community. Charlene Prickett willcollect names, addresses and phone numbers of all Mount Royal residents wanting to join together forone of several treatment windows scheduled between June19 and July 9. Each property owner willpay his own treatment bill to ArborCare and, as a part of this treatment schedule, will enjoy thereduced group rate. ArborCare will phone each resident to plan treatment, set up dates, etc.
To sign up for treatment, email name, address and phone number to Charlene Prickett [email protected]. Call Charlene with questions at 244-6621. For questions regarding treatment protocol, contact Bonnie Rogers at ArborCare, tel 273-6378.

Source: http://mountroyalstation.ca/History/tree_treatment_jun2007.pdf