Victoria, BC (on Vancouver Island)

Very nice. No obvious brown-rot-caused "witch's brooms," which are so common on spring cherries in Vancouver. It makes me wonder if this plant is on its own roots.

 

Good morning Douglas, can I ask why witches brooms are common in Vancouver ? Perhaps compared to other locations.
I found this comment by you fascinating.

 

Note that these are not the phycoplasma-related witch's brooms we associate with dwarf conifers. In cherries the witch's broom is an ugly proliferation of ragged branches caused by a systemic infection by brown rot disease. Brown rot infection is common on susceptible species like Prunus itosakura (syn. P. subhirtella) and is facilitated during mild, wet weather. In Vancouver, we can have rain without a break for days and days in the early spring (and in autumn and winter).

The problems usually start with a flower infection (blossom blight), which spreads into the surrounding tissue, killing back the tender vegetative growth (twig blight) adjacent to the flowers. Perennial cankers in the twigs produce spores for subsequent infections. Later regrowth from behind the original damage may become infected if the rain persists, or avoid infection and extend for some distance if the weather is cool and or dry, only to be infected in a subsequent season. The result is a rat's nest of dead and live branches.

Grafted cherries seem to be most at risk. This is probably (I'm definitely speculating here) because of increased susceptibility due to stress related to differential growth—the two species, P. itosakura and P. avium, pushing growth at different times or rates. The particular P. avium cultivar used as grafting stock in British Columbia is 'Mazzard F12/1', which is very vigorous (well matched to 'Kanzan'). On the other hand, perhaps P. itosakura cultivars like 'Autumnalis Rosea' are just
too prone to infection because of the wet conditions here.

We at UBC Botanical Garden have been experimenting with a variety of cherries, growing brown-rot- and bacterial canker-susceptible cultivars on their own roots to compare with grafted plants. Initial results look promising, but it's still early days.

 

@Douglas Justice, thankyou Douglas for the very informative reply. I have learnt a lot today about brown rot causing witches brooms in Cherries. I wonder if the environmental changes we are all witnessing the world over is the main contributing factor with this problem. Though here in the UK we are experiencing very warm but very dry Springs these last couple of decades, so your theory of climatic effect on Cherries will probably not be noticed as it is in Vancouver.

 

A 'Whitcomb' cherry with lots of flowers at Government House was just posted on Facebook by CBC Radio North by Northwest. I think this page is public.
Facebook
There were no flowers at all last week on this cultivar in the Peter Wharton Grove at UBCBG.

 

Four ‘Shirotae’ at the Kids Play Area.
Swartz Bay Ferry Terminal.






I noticed a wasp trap in one of the trees.

 

Four mature ‘Akebono’ on the lawn south of the old ‘Empress’.


Found some petaloids.

 

Twelve ‘Shirotae’ blooming now at the Hotel Pacific Grand on Belleville Street.

 

Several mature ’Rancho’ on both sides of George Street from Olive to Moss.



Largest ‘Rancho’ I have seen anywhere.

Look at that girth ( on the tree, not the cherry scout).

 

More ‘Rancho’ on Chamberlain, from Oak Bay Ave to Brighton St.


Looks like the trees have been pruned due to power lines.

 

Beautiful tunnels of ‘Akebono’ for 3 blocks on Moss St from Clover to May.
Co -existing with power lines.

 

We have tree huggers over here as well, glad to see its a pastime on your side of the pond.

 

Lots of ‘Akebono’ blooming on Harbinger, north of Fairfield. Even one with a swing.

 

Nice pair of ‘Akebono’ at YMCA on Courtney Street, near Christ Church Cathedral.

 

Good-looking pair of 'Akebono' blooming on Milton Street, north of Franklyn Street in Nanaimo.

 

Four 'Yae-beni-shidare' on driveway at Davis Rd, north of Battie Dr in Ladysmith.

 

My friend Wanda was kind enough to take me on a mini cherry scouting drive from Ladysmith to Departure Bay ferry terminal this morning. Lots to see.

Here is a nice 'Snofozam' in Ladysmith - not pruned to look like a mushroom.

 

'Beni-shidare' still looking good today at Brown and Stillin in Ladysmith.

 

Also at Brown and Stillin in Ladysmith is one 'Accolade' still in bloom today, but past it's prime.

 

Here is a mushroom-shaped 'Snofozam' at Dunsmuir and Coburn in Ladysmith.

 

Five young 'Yae-beni-shidare' on driveway in Saltair. On Chemainus Rd and Porter.

 

Four 'Akebono' on Pine Street, west of Daniel Street in Chemainus.

 

Five 'Akebono' at Chemainus Post Office. Substantial trunks.

 

Nice 'Akebono' on Beach Drive and Ocean Terrace in Nanaimo.

 

'Yae-beni-shidare' in competition with it's rootstock at Cilaire and White Eagle in Nanaimo.