Thursday, March 12, 2015

Azaleas and Rhododendrons


Duff and Donna Evers garden in Halifax, N.S

A few years back I came across a very well-dressed couple who were maneuvering a large cart filled to capacity with rhododendrons toward a nursery cash register. 

No doubt they had selected the rhododendrons because their clusters of trumpet-shaped flowers were spectacular, but I had to wonder if they had any idea what they were in for. 

Growing rhododendrons in Southern Ontario is not impossible, but with our hot, dry summers and harsh winters, it is a challenge that is not for the faint of heart. More importantly the soil here is not likely to be the rich, sandy loam rhododendrons and azaleas prefer. Noticeably absent from the couple's cart was anything to amend their soil.

As I watched them take their place in the cash register line up, I couldn't help but adopt the pessimistic view that the future prospects for those mauve rhododendrons was pretty bleak.


I can speak personally to growing rhododendrons without much of a clue. 

Years ago I bought a rather fine looking specimen myself. I made a half-hearted attempt to amend my soil, stood back and hoped it would just do its own thing.

But the rhododendron sulked and dropped its leaves when the summer got dry. Two years later it was so spindly and pathetic I banished it to the back of the yard. There it mocked me by flowering the following spring.

I was beginning to feel hopeful that my rhododendron might actually begin to prosper when the big tree damaged in the ice storm had to be cut down. Hubby was the cleaning up afterward when he came to me with a rather trampled looking shrub in his hand.

"Was this important?" he asked. 

He was holding what was left of my poor little rhodie!  

(Read an article: Ten Ways to Kill a Rhododendron by Marjorie Hancock here.)

The Dalhousie University Agricultural Campus in Truro, N.S.

Those of you who have been following this blog for awhile will know that last summer I visited Nova Scotia. On the east and west coasts of Canada, rhododendrons and azaleas flourish. There is plenty of rain and the soil is the rich, acidic soil that they require to grow well.

Rhododendrons can be grown elsewhere. We just have to work a bit harder to give them what they want.

Site Requirements:

Notes on the Atlantic Rhododendron & Horticultural Society suggest that site selection is a key consideration. If the planting area you are considering is wet at any time during the year, it is not a good option. Like so many plants, rhododendron's hate wet feet. 

How do you test a site's drainage? 

The Society recommends digging a hole and filling it with water. If the water does not drain quickly, select an alternate location.

The Society also warns against planting rhododendrons near foundation walls on the south and west sides of buildings, as they can become hot spots that rhododendrons do not tolerate well. A roof overhang is also an issue, as they can keep vital moisture from getting to you rhododendron.

One final important consideration- choose a site protected from the wind. Get more tips on siting your plants here.


Light Requirements:

What do you think: sun or shade for rhododendrons? 

Most people think shade, but in reality experienced gardeners like my friend Donna Evers advise differently:

"Despite what the books say about growing rhododendrons in shade, we have found that in our garden they do better with sun. They are more compact and have a better bud set."

A general rule of thumb with regards to light requirements is based on leaf size. The larger the leaf, the less sun is required. Small leafed varieties require more sun. Generally speaking most rhododendrons need at least half a day of sun.

The Dalhousie University Agricultural Campus in Truro, N.S.

Soil Requirements:

Rhododendrons and azaleas like well-drained, acidic sandy loam ( pH: 4.8-6.0) with lots of organic matter.

Donna, whose garden you see in many of these pictures, passed on this excellent advice about soil conditions that she got from the late Captain Dick Steele, a well respected Nova Scotian rhododendron breeder:

"At first we didn't feed our plants, but then I asked Captain Dick Steele about fertilizing them and he replied, "You feed your kids, don't you?" On his advice we started broadcasting scant handfuls of an all purpose fertilizer (10, 10, 10) over all the gardens. What an improvement it made! We also apply a layer of shredded oak leaves every year. This has improved the soil immensely. Good soil is where it all starts."

Read more about soil requirements here. Read up on feeding hungry rhododendrons here.

Duff and Donna Evers garden in Halifax, N.S

Duff and Donna Evers garden in Halifax, N.S
Planting:

Start by purchasing healthy plants. In colder areas of North America, rhododendrons are best planted in early spring. The American Rhododendron Society recommends planting in fall for hot areas of the country.  

Rhododendrons and azaleas are easily damaged or killed when they are planted too deeply. The top of the root ball should be level with the surface of the ground and planting hole should be larger than the root ball. If your soil is not the light, sandy, acid soil that rhododendrons and azaleas prefer, it is critical to amend the soil with organic matter. 

Find more tips on planting here.

Duff and Donna Evers garden in Halifax, N.S

Duff and Donna Evers garden in Halifax, N.S

Duff and Donna Evers garden in Halifax, N.S.

Maintenance

Rhododendrons and azaleas don't need a lot of care once they are properly established. Mulch your plants with pine needles, oak leaves or wood chips to guard against temperature extremes. Mulching also helps to conserve water. 

One great idea is to cut up your tree after Christmas and place the boughs at the base of your rhododendrons. This little bit of added protection will help prevent them from drying out in winter.

Finally, it is best to remove spent flowers as it prevents seed formation and encourages new growth.

Duff and Donna Evers garden in Halifax, N.S

Pruning and moving Rhododendrons:

I asked Donna for a few notes on pruning and potentially moving rhododendrons. I had to laugh at the humour in her reply:

"We haven't done much pruning except to tidy them up by removing dead branches...We do have to do a little editing this coming spring. Things have gotten a little crowded over the past twenty years. Rhodies have a large, but shallow root mass and are relatively easy to move. The size of the rhododendron and the age of the gardener are the determining factors. Our solution is to give the biggest ones to our kids:-)"

Find additional tips on transplanting rhodies and azaleas here.

The Dalhousie University Agricultural Campus in Truro, N.S.

Duff and Donna Evers garden in Halifax, N.S

This is Rhododendron 'Teddy bear' in Donna's garden. The brown indumentum on the underside of the leaves has a soft, furry texture. Donna tells me that, "Gardeners grow it more for the leaf than the bloom." 

Duff and Donna Evers garden in Halifax, N.S

Duff and Donna Evers garden in Halifax, N.S

Insect and Disease Control

It is a best to seek local advice for the control of insects and disease as problems can vary according to region. Nymphs on the undersides of leaves may cause yellow spotting. Root weevils and stem borer are other widespread pests.

Find ways to address insect and disease problems here.


The Dalhousie University Agricultural Campus in Truro, N.S.

So why would someone like me want to try again to grow rhododendrons or azaleas? My pictures answer the question for me. 

They're gorgeous! 

We gardeners learn by trial and error. If you don't succeed the first time, you can always try, try again.

29 comments:

  1. Hi Jennifer, I am fortunate that I am able to grow rhodos and azaleas in my garden (southern Ontario zone 5b. Mine are situated in front of a tall hedge facing southeast which helps a lot with wind and winter. It is a fairly shady area although they do receive morning sun, about 3-4 hours worth. I do not get the amount of blooms as Duff and Donna do, but they are healthy and bloom every year. Mulch is important, usually fine pine bark or pine needles if I am lucky. I mulch in spring and before winter. I do add some soil acidifier early spring to help with the blooms. In drought I water as they are shallow rooted. I do prune very occasionally to keep them from getting too leggy - that is a learning experience! Perhaps this information will persuade wanna be rhodo growers to give them a try.

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  2. You have done a very thorough job of explaining how to grow them in Ontario. I have a few. They bloom but are not happy (except for one azalea). The main reason is that the garden in on pure limestone. I planted them straight on the rock, on top of about a foot of peatmoss and I mulch them with compost every year. I am surprised they have survived given how basic the soil is.

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  3. We have a few rhodos here, I think I can say that the ones that receive a few hours sunlight flower better than the ones in the woodland where only one out of 5 flowers regularly. Obviously I need to give them more TLC!

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  4. Jennifer, thank you for this GREAT post and gorgeous pictures! Fortunately, my garden has right soil for rhododendrons. My biggest problem are pests that damage leaf' edges.

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  5. Hello, Jennifer! What a wonderful blog I just found!
    Thank you for this informative and very beautiful post.
    Having a garden surrounded by coniferous woodland, I have planted two rhododendrons last year.
    I'm of course very much looking forward to seeing how they survived their first winter.
    Have a lovely weekend!

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  6. Rhododendrons or Azaleas ....... the blooms are just gorgeous (can you describe plants / flowers as gorgeous?) They look beautiful and bring such delight.

    Lovely pictures again, thank you.

    All the best Jan

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  7. I grow lots of native azaleas and a few rhododendrons. The rhododendrons seems to struggle more. I may have to amend their soil after reading your post and relocate a few to a sunnier (morning sun) location. Great post!

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  8. I adore these flowers, but they will not grow in my clay alkaline soil....I even tried to amend the soil but no dice. I have one small one that barely hangs on or flowers anymore.

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  9. Jennifer, thank you for such interesting information and pictures. I grow 10 rhododendrons and azaleas and they are healthy in my zone 5a. They winter under the snow or sometimes their buds are above the snow level. I have only hardy varieties, Finnish bred, especially for our climate. All grow in semi-shade place, in acid soil and bloom wonderfully.
    I hope to see your blooming rhodie!

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  10. Coming from the West Coast where the Rhodies are like weeds, it's hard to not see them all over up here. But our summers are too hot, and like you, too dry. There are the Yak's, and most likely a few more varieties that will do well up here, but I feel too bad about wasting water to give them a try, LOL.

    A beautiful post, I"m pinning it, because it's so well written, and beautifully photographed that it should be required reading for anyone who is looking to add the stunning beauties to their garden.

    Jen

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  11. Your photos are absolutely breath taking. When I lived in Alabama I loved my azaleas and rhododendrons. The ones that are hardy in my area now are the deciduous azaleas. I'm not quite as fond of these altho the flowers are lovely and they come in a range of beautiful colors.

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  12. Hi Jennifer, thanks for all the interesting info. I am fortunate to have perfect soil and climate for rhododendrons in my garden, I just wish I had space for many more than the three I have :-)

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  13. Beautiful, I have a rhododendron that I love. :-)

    http://tinajoathome.com/

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  14. Great advice, Jennifer. We have had some success growng rhodos in our SW Ontario garden - in the shade with some diffused sunlight later in the day. My tip is to make sure you protect them from the harsh winds during the winter - we tent ours in burlap.

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  15. What lovely photos. I have killed as many Rhododendrons as I have planted. They are tricky in our climate, however, azaleas grow like weeds here.

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  16. These are gorgeous, Jennifer!
    I especially love that pink-peach colored one. So beautiful.

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  17. Gorgeous plants, i love the colours and the papery crinkly petals. I used to grow them, but they weren't happy with the tough love regime they were subjected to, and the bugs that suck the moisture out of the leaves were happy and thrived.

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  18. One look at all your beautiful photos certainly answers your last question, Jennifer. I love azaleas and rhodies, but azaleas in particular don't do well here. I received two free azaleas two years ago that were iffy for my zone. I circled them with burlap last winter and mulched them, but then we had the worst winter in twenty years, and most of the shrub died off. There was just enough green on the bottom of each last summer that I had hopes they would bounce back. But I completely forgot to protect them this winter. Now I'll just have to wait and see if they survived. As much as I love them, I may just have to travel to other places to get my fix.

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  19. Beautiful, beautiful photos. My beloved rhody looks awful. I've just learned it's a bug issue and my only two options are, live with the horribly ugly leaf situation, or whack it to the ground in an attempt to start over. It's so sad. :(

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  20. A lot of important information and beautiful photographs in this posting, Jennifer. I grow a few azaleas and one rhododendron here. I am fortunate that they don't require much attention from me in my Northeast garden. I'm not sure, however, how well the rhododendron has survived this brutal winter. P. x

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  21. What a gorgeous garden - great information - so hope that newbees, and those who've had troubles in the past find it....I'm thinking I'm going to tweet it, now that I have my new account! Did my Canada Blooms video - and purchased a Yeti mic - excellent and easy to use ($169 all in) - can be used with a boom as well. Great to see you on Saturday. I've got more grass than snow now, so it won't be long!

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  22. What a useful post and ablaze with divine colour! I am a fan of both, they are such easy plants to grow and rarely sulk here, in fact they are often found growing wild!xxx

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  23. Help! My azalea and rhods are now in a full sun location due to the removal of at least six 50+years old White Pines. Almost my whole yard is now ablaze with the hot sun... it faces southeast... so it will be like that sun up to sundown. Can I move them under an old crabapple that has all it's growth at the very top? Would I have to amend the soil? Not sure about the root systems of old crabapple trees.
    Any suggestions would be most appreciated. Thanks in advance, Annie

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    1. I am facing a similar garden upheaval (last summer we had to remove 3 big trees) so I can imagine what you are going through. I do know that Rhododendrons have a fairly shallow root system so it is possible to move them. I would think that fall is the best time to do so.
      A friend of mine knows more about rhododendrons than I do. Let me ask her what she advice she has, and I will come back here with another reply.

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    2. Hi grannieannie, Here is my friend Donna's reply. (Donna has beautiful rhododendrons and azaleas in her garden in Nova Scotia.):


      Did the lady say where she lives? If she lives in a climate similar to NS rhodies can take more sun. If she is in the southern states they will need shade. I don’t think azaleas should have a problem with sun, especially deciduous azaleas. Even evergreen azaleas can take more sun in NS.
      We move our rhodies and azaleas after they have bloomed. It is important to keep them well watered right into the fall This gives them a chance to set buds for the coming year. They are shallow rooted which does make them easier to move but if they are very large it can be a big job. The soil should be amended with fresh soil and compost. Our soil is so acidic it isn’t necessary to add rhodo fertilizer.It is most important not to plant too deeply. I don’t think the roots of the apple tree will interfere and it should provide some shade.
      It is difficult to give advice with so few details an article on the ARSociety website helpful on Transplanting Rhododendrons and Azaleas.The American Rhododendron Society is an excellent resource.

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  24. Jennifer, do you remember at exactly what time of year you were here in Nova Scotia? Peep #1 says she HAS to visit the Truro campus next year when the azaleas are in full bloom. That soft pink one is divine!

    Purrs,
    Seville

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    1. My camera records that I was there on June 7th, 2014 and took the pictures at 1:30-2pm. The campus doesn't have a huge collection, but you can always check out the rock garden as well (the rhodies I photographed were opposite the rock garden). Well worth a visit!

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  25. Early June, you say? EXCELLENT! Thought I spotted some primroses in one of your pictures which made me wonder if you had been there in May. Peep #1 will definitely be going to Truro this June. purrs

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    1. Early June would be the perfect time to go. I don't remember a lot of primroses (the garden is too dry I think), but the garden is really well worth seeing in early spring.

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