British Columbia: SOLVED: Disease on Garry oak Seedlings

I have several 2-4 year old seedlings grown from acorn and they are now in a #1 pots. Recently several have shown signs of what I believe may be Oak Wilt but upon checking the CFIA information sheet I don't see Quercus garryana listed as a host (although the sheet does say "all species and varieties of oak".

Is this indeed oak wilt?

Thanks,
Michael

Note: location of plants is Saanich, BC
48.545611, -123.392873

 

Paging @Douglas Justice to have a look at this one.

 

I read your post - and I wonder - when you walk around your neighborhood (or any place where there are the native Garry Oaks on S Vancouver Island) - do you see similar leaf pattern? (ie not just drought dry leaves)

I imagine you might not find so much info re: the BC oak (garry oak) because it is such a small population in the tiny corner of SW "Salish Sea" BC (compared to the spread of pine beetle for eg) - plus some studies come from back east - and who'd think there'd be oak out in coniferous BC, so to speak.

HOWEVER - as you likely know - there are huge numbers of G Oaks in parts of western WA and definitely Western Oregon (the Willamette Valley)
https://www.oregon.gov/ODF/Documents/ForestBenefits/OregonWhiteOak.pdf

so - google around the official Oregon gov website - down there they call them Oregon White Oak (but it's still Q garryana) - and there are some papers in PDF about Oak Wilt

it says that this fungus can be spread 3 main ways:
1. underground when roots touch from tree to tree in a grove - (my amateur version)
2. a beetle that likes the sick tree sap - burrows under bark - then moves to the next tree - (again, my simple amateur version)
3. moving cut wood from site to site (hence no firewood transport for camping from one region to another or over the border)

https://www.oregon.gov/ODA/shared/Documents/Publications/PlantHealth/OakWilt.pdf
(typo re: how they spell Canada ... page 2/2)

this paper is very detailed -
https://static1.squarespace.com/sta...1e6eebb/1503519617955/oak_wilt_PRA_112011.pdf

so I wonder if one picked up acorns and germinated them oneself - or dug up soil around one's yard near the Oaks - then maybe those actions helped spread it too? Not sure on that.

In your case - if you did pick up the acorns - are the big trees above the fallen acorns - are they suffering from similar leaf issues?

does your Saanich parks department have any plant disease prevention info? (invasives, diseases, etc)

there is a "Garry Oak Preserve" near Duncan BC - owned by the Nature Conservancy of Canada - maybe they have info. There are several research projects there -
NCC: Research at the Cowichan Garry Oak Preserve

 

Georgia Strait -
Your reply to disease on Garry Oak seedlings is excellent. I am replying to keep this post among the top 5 so that, hopefully, others will see it and comment.

I'd be very interested in what Doug Justice may have to contribute.

Just as an aside on Garry Oaks, this is the first year in 12 that my Garry Oaks have not been afflicted with Jumping Gall Wasps. One expert I was in touch with suggests that the trees may be responding with increased tannin to fend them off - who knows?

Bottom line - I, like many, love these trees and hate to think that something new like Oak Wilt may lay them low.

 

yes, I think many of us love the look of a good solid Garry Oak. There is a beautiful grove of them - many acres - at Champoeg State Park in Oregon - just west of Interstate 5, south of Portland. It is the site of an old Hudson Bay Company farm (supplied Fort Vancouver, WA) - and I believe, also the site of where the settlers held the meeting to create the State of Oregon.

MARGOT - I think you'd find this interesting as it includes the Big Leaf Maples (Acer macrophyllum) Sudden Oak Death and Associated Diseases Caused by Phytophthora ramorum

I found this too (I realize it's a diff fungus than the Oak Wilt fungus)
- from UBC forestry - I can't find the date of this info paper - Arbutus | CFCG
(there's a similar paper about Garry oaks - Garry oak | CFCG)
QUOTE -
Phytophthora ramorum, a new pathogen of unknown origin causing “sudden oak death” in California and Oregon, can also damage arbutus, causing leaf spots and cankers. Since this pathogen is thought to spread rapidly on ornamental plants like rhododendron (DeFrancesco, 2001), especially in wet weather, it may become important for British Columbia in the future. (DeFrancesco, L. 2001. Sudden oak death linked to rhododendrons. Scientist 15:16-16.)

Here's something from the federal gov't of Canada
Sudden oak death – Phytophthora ramorum - Canadian Food Inspection Agency

from California - Hosts and Symptoms (shows a photo gallery of more than just oak - eg rhodo, arbutus, vine maple, pieris, etc)

from the "Oregonian" newspaper in Portland
Oregon officials find new cases of sudden oak death six miles north of quarantine zone

 

Sorry to come late to this conversation.

@mcroteau1969 - researchers at the CFS Pacific Forestry Centre on W. Burnside Road have been studying SOD and P. ramorum since the mid-2000s. You could bag up samples and take them there for identification/verification. At the front desk, ask for Dr. Joey Tanney or Dr. Simon Shamoun.

 

Of course you want to find out what is causing those amazing colours on your Quercus garryana seedling leaves. I've never seen anything like that before - almost beautiful. From what I've been reading, I think you should be optimistic that it is not Phytophthora ramosum (Sudden Oak Death).

On this website for example it sounds like the symptoms of SOD on the oak species they mention are mostly stem cankers; no mention of leaves. Sudden Oak Death and Associated Diseases Caused by Phytophthora ramorum

Also, looking at online photos of plants afflicted with SOD, there are none that look anything like the leaves in the photos posted.

When you do find out what is going on with your young trees, I know we'd all be very interested to hear.

PS Did you know that there has been a conversation going on on this forum recently about the discovery of SOD at a nursery in Sanichton on Vancouver Island? See Plants in the News - Phytophthora ramorum - again.

 

Thanks for the suggestion - if I can find any samples similar to last year I will do that. Haven't seen it thus far.

 

I don't believe this is SOD but then again - I'm no expert. As MK3.1415 suggested, I will try to locate samples with characteristics similar to last year.

Yes, I have heard about the P. ramorum at the nursery. Sad, they are such great people who run that nursery and I would hate to see the business fold as it is an integral part of the Greater Victoria landscape business.

Thank you for your interest in my post!

 

UPDATE:

I contacted staff at the Royal BC Museum and believe I have received an answer so i now consider this matter solved.

Leaf Scorch http://hortsense.cahnrs.wsu.edu/Public/FactsheetWeb.aspx?ProblemId=472

Leaf scorch has many possible causes. Plants that are under stress (such as from drought or heat) may not provide sufficient water to leaves, causing the edges to turn bronze, then later brown and dry. In severe cases, the scorch may spread to areas between veins or entire twigs may die back. Trees placed near heat-reflecting surfaces such as buildings or pavement often suffer from heat stress. Other possible causes of scorch include damage to roots or stem, soil compaction (which can cause reduced drainage resulting in root damage), or the presence of excessive salts from overuse of chemical fertilizers.​

Descriptions online and the above site seem to support this conclusion and the symptoms did not reoccur in 2019 after a change to watering and fertilizing practices.

Thank you all for your assistance.

 

Glad you where able to solve that issue. Odd really since there's no such issues I've seen on any native Garry Oaks from Victoria up to my area in Courtenay. The trees around here where really loaded with seeds/acorns this year.
Cheers, Barrie.