Anyone growing Rhododendrons?

dukeofdoom · Post by **dukeofdoom** » Sat Oct 20, 2012 2:36 pm

So far I have about 5 different kinds including some azaleas.

I like how glossy their evergreen leaves are, and in bloom, they look tropical to my eyes.
The problem I have is that they seem to bloom for a very short period in the spring only.

I came across this link, claiming that you can get different varieties to get blooms through out the year.

http://www.flounder.ca/KomoKulshan/12-m ... ndrons.pdf

I'm on the east coast, so I'm a bit sceptical, as these plants seem much happier in a west coast climate.

Does anyone have experience with Rhododendrons blooming in summer, fall or winter on the east coast?

[edit]
Rhododendrons in a tropical setting
http://www.mooseyscountrygarden.com/gar ... val-2.html

canadianplant · Post by **canadianplant** » Sat Oct 20, 2012 5:41 pm

*Waits for Paul to pipe in*

I have 4 (2 Rhodies, 2 Azalea) up here. R. "Helikkii", R."PJM" hybrid, Azalea "Lollipop" and Azalea "mandarin lights".

The PJM flowers in april or may here, then the lollipop in may, then the Helikkii in June. Im not sure when the Mandarin will flower, this is its first winter. I wouldnt mind trying a few more types if anything catches my eye. Im also pretty sure there are a few native rhodies to the east coast, like Rhododendron maximum:

http://en.wikipedia.org/wiki/Rhododendron_maximum

Here is a link that shows some native ones:

http://scholar.lib.vt.edu/ejournals/JAR ... -roane.htm

Paul Ont · Post by **Paul Ont** » Sun Oct 21, 2012 12:29 pm

On the East coast you can probably get blooms from March until August, then some will flower in autumn, but not well.

Yes, i grow a number of Rhodies, absolutely irreplaceable in the cold tropical themed garden, especially the large-leaf varieties. Check out R. sutchuense, calophytum, praevenum etc. and their hybrids on the Rarefind website for some ideas!

TimMAz6 · Post by **TimMAz6** » Sun Oct 21, 2012 3:12 pm

Rhodo's are a very common planting here in USDA zone 6b..........likely the most common foundation planting.

Cameron_z6a_N.S. · Post by **Cameron_z6a_N.S.** » Mon Nov 05, 2012 9:45 pm

Rhodos are also an extremely common planting here in Halifax. In much of the city, it seems as if every second house has one in their front yard!

Paul Ont · Post by **Paul Ont** » Tue Nov 06, 2012 7:56 am

Ya, not so common here at all. They just don't grow well. It's too much work for people to amend the soil for proper growing conditions, at least that's my theory.

canadianplant · Post by **canadianplant** » Tue Nov 06, 2012 8:39 am

Paul Ont wrote:Ya, not so common here at all. They just don't grow well. It's too much work for people to amend the soil for proper growing conditions, at least that's my theory.

That or people assume they arent hardy. Maybe people assume they are like the southern azalea thats everywhere.in the SE states

TimMAz6 · Post by **TimMAz6** » Tue Nov 06, 2012 7:44 pm

Rhodo's need acidic soil............our soils are very acidic......generally 4.5 to 6.0. I'm guessing areas where Rhodo's aren't common have higher ph soils........limestone soils?? If you get Rhodo's make sure you reduce the soil pH and don't use lime or limestone near the Rhodo roots!

canadianplant · Post by **canadianplant** » Wed Nov 07, 2012 4:41 am

Thats what I dont get: Rhodos like acidic soil right? Most house foundations are concrete with is lime if Im not mistaken. So wouldnt them being foundation planting be a bit of an uphill battle?

My area is mostly muskeg (peat bogs), tons of pine, so you would think my soil in the city is acidic right? Well its at best neutral. I plant rhodies in a 10:1 ratio of peat moss:native soil, and toss on a deep layer of coffee grounds and pine needles every year. The Helikkii does fine, and the PJM is too new for me to say anything, but I think they do well in relatively higher PH then most rhodies. My "lollipop" Azalea does well, in 50/50 peat/native soil but grows slow.

Has anyone tried watered down coffee? I know there is a bit of a debate in regards how well coffee grounds acidify the soil, but the actual coffee itself would be more acidic and more readily absorbed would it not?

dukeofdoom · Post by **dukeofdoom** » Wed Nov 07, 2012 7:21 pm

I have family in Seattle that also own a few coffee shops. They used many buckets of the left over coffee grounds for amending their soil. I'm not sure how much it helps to make the soil acidic, as their soil is probably pretty acidic to begin with. Their garden does grow very well, so its probably beneficial, it can't be harmful. They did have a problem with rats moving into the garden and eating the coffee grounds, so I think they stopped adding it now.

I live in Windsor (Ontario) and very few people have rhododendrons here. The biggest ones I've seen are about 4 feet tall, but the branches are sparse and not anywhere as nice as I've seen on the west coast. I'm not sure if the soil is the problem, or our hot summers, or home owners not planting them properly. We seem to get enough rain through our the year, maybe a month in the summer is a little dry. Up to about last year, very few of the local stores actually carried rhododendrons. So it might be that few people planted them because they were not widely available.

Overall, I think these plants can do well here in or Southern Ontario climate, if all conditions are controlled properly.
There is a small public garden in Amherstburg (neighboring city) just dedicated to these plants.
They were planted 25 years ago. They are grown under magnolia trees, on top of specially built raised beds of about 3 feet tall with the proper soil mix.
Some plants are up to 6 to 7 feet tall now, and there are about 700 of these plants planted there.

Some photos:

http://www.flickr.com/photos/33535417@N ... otostream/

Here's a link and more information... its a very pretty town to visit.

RHODODENDRON & AZALEAS GARDENS NOT IN OUR BACKYARD . . . . . IN AMHERSTBURG, ONTARIO: King’s
Navy Yard and Seagram’s Park in Amherstburg boast of more than 700 Rhododendrons & Azaleas all lovingly
planted and cared for by the AA&M Rhododendron Committee. Founded in 1985 by Bob Sutherland, this
Committee is an incorporated group consisting of 11 enthusiasts who, since 1988, have worked with local City
officials to create two outstanding public gardens, the King’s Navy Yard on Dalhousie Street in Amherstburg and
Seagram’s Gardens on County Road Twenty adjacent to the Seagram’s Distillery. Starting in 1988 with Roseum
Elegans, the gardens today are comprised of equal numbers of lepidotes and evergreen azaleas. New beds are being
created this Spring to house an addition 85 plants. The varieties include a large collection of the little known
Stanton series of rhododendrons and azaleas, all developed on neighbouring Gros Isles, Michigan. Paul Morneau,
current president of the Committee, says that growing rhododendrons and azaleas in these gardens is a challenge
because of the clay that is the natural soil in the area of the gardens. “We grow these plants in raised beds”, he says,
and “we use a lot of shredded pine bark mulch mixed with whatever peat moss and compost we can get. If we can
grow rhodos and azaleas, anyone can”. Not only is the clay a problem, so is the heat and watering required. Paul
employs a misting system, developed from greenhouse spray nozzles. This system creates a fine mist over the
plants in the hottest of days, is parsimonious in the use of water and cannot waterlog the already very porous raised
bed. Those visiting the area will find great interest not only in the rhododendron and azalea plantings, but also in
the wide range of historical sites.

canadianplant · Post by **canadianplant** » Thu Nov 08, 2012 3:54 am

IT could be just a combination of all the above said reasons lol. In my area, no one really grows anything "worth while". For instance, we can grow various amounts of apples, plums, pears and some cherry trees, but people only plant macintosh apple for fruits. The same goes for rhodies, because people think that they wont make it here, and when they do actually plant it, they usually plant them in full sun, exposed to winds ETC.

The ones you see planted that are leggy and not happy are probably due to not amending soil, too much sun (too warm in summer), possibly wrong species etc. The best thing to do is to grow some properly and spread the word. When I go to nurseries Im always helping people with there plants, especially stuff like Rhodies, which people concider exotics up here. I have some people interested in growing bamboo because theyve seen me have success with it.

If you want to get a real easy one to start with, grab a PJM hybrid. They arent as fussy over acidic soil (relatively for rhodies

), they can take a lot of sun up here, are extremely hardy and bloom heavily. The blooms are a sortve lavender/lilac colour, and they dont take up too much room. They are also readily available. They bloom in early may, even up here! My grandma has had one for a good 10 years, and it is definitely one of her nicest plants. IT also turns a bright red in fall, and a dark burgundy in winter.

As far as the coffee grounds go, I believe the most accepted information says it helps iron uptake in acidic soils (which, isnt a bad thing at all!). I think it helps chlorosis (yellowing) of the leaves. Also, concidering coffee is highly acidic, I would assume that it would do SOMETHING in terms of acidiying soil, even to a small degree. The best thing to do is plant them under pine trees so that they get a natural mulch/acidic soil as well as good dappled light, which most rhodies seem to like. THe pine needles slowly create acidic conditions. I also plant them in 90% peat in an area where mostly acid loving plants are. Each plant was planted using peat in varying levels, but eventually that whole area will be acidic to a point.

TimMAz6 · Post by **TimMAz6** » Thu Nov 08, 2012 10:40 am

the lime in the foundations must not contribute much to raising a soil's pH since Rhodo's THRIVE here. Even the Hydrangea blooms are blue near the foundations. If the pH was high the blooms would be red. Don't worry about the concrete foundation, reduce the soil pH and use a thick wood mulch to keep the roots moist.

lucky1 · Post by **lucky1** » Thu Nov 08, 2012 8:56 pm

Ditto to everything Tim said

.

Some websites suggest using Sulphur...flowers of sulphur, or elemental, but apparently it takes years to change pH that way.
I'd go with applications of Aluminum Sulphate two or three times every growing season.

Barb

Paul Ont · Post by **Paul Ont** » Fri Nov 09, 2012 8:05 am

Aluminum is very toxic to Rhodies even at relatively low concentrations, best to avoid it completely! Similar to calcium, Rhodies are just really effective with using it at low concentrations, so when these elements are available at higher levels, the plants poison themselves!

lucky1 · Post by **lucky1** » Fri Nov 09, 2012 8:51 am

Aluminum is very toxic to Rhodies even at relatively low concentrations, best to avoid it completely

Wow, sorry.
The safe method then is to stay with a ton of Epsom Salts.

Thanks for the correction Paul.

DesertZone · Post by **DesertZone** » Sat Nov 10, 2012 6:08 am

Here's a good read on PH scale.

http://ag.arizona.edu/cochise/mg/pdf/Jun10.pdf#VG

lucky1 · Post by **lucky1** » Sat Nov 10, 2012 8:45 am

Thanks for that interesting link, Aaron.

Barb

TimMAz6 · Post by **TimMAz6** » Sun Nov 11, 2012 2:23 pm

I'd incorporate sphagnum peat moss into the soil. Sphagnum PM has a pH of 4.0 or so and will keep the soil moist. I'd also place 1" depth of SPM under the wood chip mulch so any rain water will percolate through the SPM prior to entering the soil. Rhodo's are worth it. Great plants.

Also, I'm sure there is a web site out there somewhere which instructs Rhodo growers how to drop the pH of an alkaline soil.

DesertZone · Post by **DesertZone** » Sun Nov 11, 2012 8:18 pm

TimMAz6 wrote:how to drop the pH of an alkaline soil.

Try coffee grounds.

seedscanada · Post by **seedscanada** » Mon Nov 12, 2012 6:14 am

Duke, WOW! to the King's Naval Yard!! Beautiful.

andym · Post by **andym** » Mon Nov 12, 2012 5:38 pm

My soil is around 7.2. It is in fact a sub soil. Currently I am replacing around 3ft of sub soil with lime free sandy soil which i have already done with my Yucca border. Everything grows well in this soil. It is just a slow progress. Pieris, Camellias, Azaleas grow well.
I have found that Cocoa shell is extremely acidic and is useful to maintain acidic conditions. It was used in the UK to act as a mulch to maintain moisture in the ground... when we had much warmer summers

Virtually dissapeared from garden centres now.
Regarding the thread title I will try a Rhododendron but not the large leaved tree varieties with deep roots.

DesertZone · Post by **DesertZone** » Mon Nov 12, 2012 6:51 pm

dukeofdoom wrote:Some photos:

http://www.flickr.com/photos/33535417@N ... otostream/

Thanks for sharing, very nice!

TimMAz6 · Post by **TimMAz6** » Mon Nov 19, 2012 1:52 pm

I was driving today and noticed a couple Rhodo's which are out of control......most people don't let them get this large so close to the house.

<img src=http://i30.photobucket.com/albums/c309/ ... 17CC4D.jpg>

This house is next to the house in the first photo. I actually drove by the Rhodo's and turned around to take the photos.
<img src=http://i30.photobucket.com/albums/c309/ ... 7E50D0.jpg>

lucky1 · Post by **lucky1** » Mon Nov 19, 2012 4:01 pm

Wow...there's a house in there?

DesertZone · Post by **DesertZone** » Mon Nov 19, 2012 5:32 pm

I had no idea they got that big.

canadianplant · Post by **canadianplant** » Mon Nov 19, 2012 5:35 pm

Aaron, Rhododendron Maximum can get 30 feet in ideal conditions:

http://www.hort.uconn.edu/plants/r/rhomax/rhomax1.html

TimMAz6 · Post by **TimMAz6** » Mon Nov 19, 2012 6:14 pm

I've seen much large Rhodos...........I'll try to keep an eye out out for the really large Rhodos. Most of the time people rip them out since they are most commonly planted near building foundations.

TimMAz6 · Post by **TimMAz6** » Fri Dec 14, 2012 6:05 pm

I was at the University of Rhode Island botanical garden yesterday. They have 50+ different Rhododendrons. A few 'unusual' looking Rhodos which were drop dead gorgeous.

Great looking leaves....no name:
<img src=http://i30.photobucket.com/albums/c309/ ... CABA11.jpg>

back sides were fuzzy:
<img src=http://i30.photobucket.com/albums/c309/ ... 300E3C.jpg>

Huge leaves:
<img src=http://i30.photobucket.com/albums/c309/ ... 137584.jpg>

Close up:
<img src=http://i30.photobucket.com/albums/c309/ ... 0C98F3.jpg>

Name of the huge leaf Rhodo:
<img src=http://i30.photobucket.com/albums/c309/ ... 06EA42.jpg>

Another R. fortunei......really cool in person:
<img src=http://i30.photobucket.com/albums/c309/ ... 50A16C.jpg>

DesertZone · Post by **DesertZone** » Sat Dec 15, 2012 10:26 am

Those are amazing, I wish they grew better in this part of Idaho.

lucky1 · Post by **lucky1** » Sat Dec 15, 2012 10:36 am

You went to a BG and only took Rhodo photos?

Barb

TimMAz6 · Post by **TimMAz6** » Sat Dec 15, 2012 5:21 pm

Don't get me going Barb.......for lunch break I had to walk back to my car to get papers for a client instead of spending more time in the BG. I was pissed since when the class was over it was getting dark.

This BG has a BBB Magnolia which I didn't get to see.

lucky1 · Post by **lucky1** » Sat Dec 15, 2012 9:02 pm

instead of spending more time in the BG

Would've been excruciating for me...

Another time, Tim.

Barb

PalmsNorth.com

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