I am a Hort. Tech. in the Parksville area, and am trying to determine why a number of shrubs have died--suddenly--on a property we care for. Plants include: Gaultheria shallon, Buxus sempervirens, Prunus lusitanica, and Rhododendron. The plants are located in a line, in a long, narrow bed which has a parking garage on one side, and a road-way on the other. Also running the length of the bed is a row of Leylanii, which are unaffected. There is another area which boarders on a wild area, and again none of the conifers appear infected. Irrigation appears to be functioning properly. The soil is moist, with no standing water. The plants have all died simultaneously, within the last several weeks. Physical appearance: Plants are completely brown, a few with one or two living (barely) branches. The roots are almost completely dead (brown and brittle) with the odd live tip. The fruit (on the Salal and Portuguese Laurel) is still the plant, but is covered with fungus (looks like mummy berry on blue berries.) I will take photos tomorrow, and post them. Many thanks.
Who owns the garage? Is it part of the same development as the planting or is there a property division between the planting and the structure?
Contaminated runoff from adjacent impermeable areas? Any work been done by contractors involving pressure washing, chemical treatments, cleaning etc?
Check out: PAN Pollution....Peroxyacyl nitrates. I lost a row of cedars adjacent to an air exchange grill for an underground parking lot because of PAN.
Any chance [WIKI]triclopyr[/WIKI] has been used in the area? Will kill broadleaf plants while leaving conifers and grasses untouched.
Thanks all for the ideas. The manager of the area thinks that they all succumbed to drought stress, though I find it strange that they died so suddenly, and simultaneously--also the irrigation was functional... I wonder about triclopyr, as there were also a couple daylilies that were also unaffected. May never know for sure. Many thanks again for all of your responses.
Parksville currently has no pesticide ban. They are waiting for the Provincial legislation to come into effect so they aren't being redundant and also don't waste money having the legal department putting together new bylaws. Nanaimo didn't get back to me, but from what I can gather Triclopyr isn't allowed by your regional district. They prefer IPM. Pesticides on their banned list can still be sold locally if they are legal. I did do a lot of research for you as I was bored and curious, but no-one was any help and the info on the web is a couple of years old from our part of the world. I also attempted to get information from the Ministry of Environment (***) I got the runaround on the phone from them and never was able to get a definitive answer to whether or not Triclopyr is still allowed in Canada. I know I've never used it. (glyphosates, yes) (Friday long weekend, two martini lunch....no-one was working today. Or they just weren't answering their phones) All of the cities around Vancouver have pesticide bans now and have had for a few years. I'm probably not even going to renew my applicators license as there is no need for it. All I've done for years is Integrated Pest Management. You could check the root balls. Probably it was drought, but they may have also been planted incorrectly or had girdled roots or some other problem.
If there is any possibility it was vandalism by somebody objecting to the presence of the planting they could have used just about anything sufficiently poisonous that they had on hand or purchased specifically for the deed - it wouldn't even have to be an agricultural chemical.
