Rhododendrons: When to move Rhodos in the Pac NW?

I have a Lem's Monarch that is outgrowing its location and is encroaching on a sidewalk, so must be moved. What time of the year is best for moving rhodos in our local biozone (Delta)? I have read highly conflicting advice on that online!

 

Transplanting Rhododendrons and Azaleas

A read suggests to me that now is the time

(Careful of any buried utility service lines)

I don’t think I have ever moved an established rhodo

I have planted lots FROM container to garden beds - not in heat of summer tho

I have also cut back leggy rhodos 1/3 per year over 3 yrs. (ie cut 1/3 of branches way down in Year One .... thé next batched 1/3 in Y2 etc)

That said I know an experienced gardener who just cuts the entire shrub in one « go » and the plant looks great today

 

British Columbia: - Rhododendron - can I move it now?

Hère is same question a few years ago

———
The biggest move I know of was when volunteers saved the well-known collection and moved it to botanical garden at Sechelt BC. It was in the Vanc Sun paper (Garden section)

And in local paper on coast

As well as North Shore News - note the date of the work party
Rhodo move a historic moment - North Shore News

Hère is another major move to same botanical garden in Sechelt BC - again, note the time of yr
Caron rhododendrons move to Botanical Garden

 

A cold Feb-March with snow is forecast so maybe wait until afterward this time. So the specimen doesn't have its roots cut and then immediately get subjected to penetrating frosts and Arctic winds. (Otherwise usual local transplanting season for hardy plants could be considered Nov-Feb). And 'Lem's Monarch' is not an early bloomer so it won't be pushing before this period has passed.

 

Looks like late March is my best bet then...sound good??

 

Follow forecasts and move when last cold spell is thought to be over.

 

I will. As a beekeeper I keep a sharp eye on the long term forecast. The best one I have found is Accuweather.

Thanks all for your advice, much appreciated!

 

I think out in South Delta BC - your climate esp if sheltered & south facing - you’re living in Cdn luxury climate !

Maybe I don’t know about the wind or other factors

In case I forget to go back to bees in trees topic - I don’t know if it’s a concern for the bees or the people consuming their delicious honey - but I observe so often those official govt signs saying to effect «herbicide applied » on roadside invasions of what we call Japanese knotweed ... also I caution anyone from purposely planting fireweed - yes it’s beautiful and natural and a longtime summer spot for beehives (the Old burned over logging cuts) - it spreads so fast underground rather like willow roots

Back to topic - I wonder since you are enthused about this project of rhodo move now - if you could prep your new spot for it now and then it’s a matter of digging your nice plant and dragging it over on a tarp to new spot and hopefully the plant will be happy

I think the points RonB made in the old thread (2012?) are ones to follow .... they have shallow roots relatively speaking so start digging by the drip line of the plant

As opposed to going in with your shovel by the trunk

Make a gentle mark w a felt marker where the trunk is currently at soil line (grade) before you start this dig

Thé well known forum contributor Margot often cites info that I think is valid from WSU - and it’s worth a read (Washington State Univ in Pullman - an old ag and vet school)

I will see if I can find a link and post herein

 

I'm late weighing in on this but, as someone who grows dozens of rhodos and has moved large and small ones for decades, I thought I'd add my 2 cents. Moving during the cooler, wetter months saves time and trouble by keeping the newly-transplanted shrub moist enough while it settles in to its new spot. Rhododendrons are very tough plants! If you're prepared to keep them moist during the drier months, you can move them anytime.

Besides the fact that your rhodo is becoming too large for its current position, it is not good for rhodos to grow near concrete sidewalks or walls. (See website below.) Don't even try to dig up the whole rootball of a large rhodo like Lem's Monarch. You would be surprised how small a rootball is necessary for success. This may be a good time to cut it back as well. Advice has changed over the years about the wisdom of doing so with many now recommending occasional pruning to ensure more compact growth. You may not get flowers for a year or two but it could be worth it in the long run.

A penetrating freeze is less of a concern in Tsawwassen than other areas in the Lower Mainland. On the chance that one could occur, be sure to apply a generous mulch (keeping the mulch from touching the trunk). This, and lots of other excellent information about Rhododendrons can be found on the American Rhododendron Society website http://www.rhododendron.org/ under "Plant Culture and Care - Planting".

Here is Rhododendron 'Mrs Tom H. Lowinsky' which I moved about 3 years ago with perhaps a 2 or 2-1/2 foot rootball. It had been growing in too much shade and was very tall and lanky. Now, 3 years later, it's full of buds for a great show this spring.

PS Thanks for the tip about AccuWeather.

 

Hello @Georgia Strait - I'm sorry I didn't see your link (http://rhododendron.org/transplant.htm) where the advice to dig "as much root as possible" seems to apply more to azaleas, rhodos growing in tough places or large-leaf rhodos. It's a bit ambiguous to me anyway and I know from experience that most rhodos can be moved successfully with a relatively small root ball.

Here is posting I found on May, 2004 from Chris Klapwijk (Chris and his wife, Sue are very well-respected rhododendron experts in BC gardening circles) -

We regularly move large Rhododendrons from our farm in South Langley.
A few Azaleas are tap rooted, but the vast majority of Rhododendrons are shallow rooted, between 30 cm to 45 cm (12" to 18").
The attached photo shows a 3.5 m (12') Rhododendron 'Pink Pearl' being moved April 18th, 2003. It was re-planted on top of the ground with soil mounded to it rather then in a planting hole. We found survival rates to be greater this way. It was kept well-watered all of last summer and bloomed profusely this year.
As far as providing shade is concerned, a word of caution. Some rhododendrons will do poorly if shaded whereas others need shade to thrive. If you know the variety you have or if you could post a picture of it in bloom I might be able to tell you what is best for your particular plant.

 

Hello Margot - does the WSU have any advice about moving large shrubs etc

I know your cited the website recently tho I forget the topic subject line

It is the website w various articles incl one about the 1980s 1990s popular « transplanting Solution » (I used it)

——-
A cousin on Vanc Island just a bit south of you has an extensive rhodo collection that’s been dug up and moved and planted in very amended soil next to ocean (it’s hot dry summer / cold shade winter)

I would say this process has been over the last 4 decades

So far so good

Their style is more like « one of each » because of their science interests — whereas i like 3 of same! (For design interests)

ÉDIT to add - i meant to say above that this cousin garden full of so many diff rhodos - yes I would say they amended up vs digging in — just like the explanation you posted above suggests

But never above the natural soil line on the trunk

Sometimes I think a few trips out to Manning Park BC to observe quietly the natural forest rhodos is more informative than one would expect

Also - one thing I wonder is — small leaves on rhodo can tolerate more sun // large leaves on rhodo indicate a plant that is meant for forest shade (generally speaking)

Compare - for example - the very common and lovely PJM —- to another small rhodo like (I think I’ve got the name) « Percy Williams » (I will have to double check) ÉDIT TO CORRECT PLANT NAME - it’s Percy Wiseman
(And it does look like the photo on this link about 2004 PacNW fav rhodo)

http://www.rhododendron.org/roy04nw.htm


My PJM just reaches and stretches for light

Whereas Percy W is happy to rein (as advertised) thé mature at 10 yr size of approx 4x4 feet and is very compact (not leggy)

 

Another good old thread - again someone points out « mounding » versus digging a big kettle hole

Rhododendrons: - Help - Really Sick Rhododendron! | UBC Botanical Garden Forums

 

Thanks all... as for trimming back, someone has been pre-emptively pruning all the buds and branches off the rhododendron that even look like they will encroach on the sidewalk. I had pruned it back last year, resolving to move it in 2021. But this "volunteer" sculpting has made that an imperative. So...the problem is not pruning before moving but rehabbing the plant post move to hide the damage to the (soon to be former) street side.