Rhododendrons are Interesting in Summer

Growing rhododendrons may have an ultimate aim for beautiful flowers in the spring months, but other features provide interest at other times of year. Flowers only last 2-3 weeks, so it is good to have virtues all year. 
Many of the rhododendrons we grow have been selected for interesting foliage. The emerging new growth shows  great variety in leaf form, texture and colour.
One of our all time favourites with respect to wonderful foliage was a cross of (R. yakushimanum x R. pachysanthum) done in 2001 by Joe Harvey from B.C. Many of these plants have found their way into the gardens of ARHS members, but some have stayed with us. We have dubbed then "Blue Heaven" because of the lovely blue-gray tomentum that appears each summer. 

All have nice furry indumentum which stays after the tomentum wears off as the season progresses.
We have a duplicate seed lot(ARHS06#49) of this same cross grown in 2006. Many show the nice characteristics of the 2001 plants. There is some variation in degree and amount of tomentum. It is remarkable that the plants from the 2001 seeding have not bloomed yet. We are not really disappointed in that feature since they more than hold their own in the garden.

R. pachysanthum is quite predictable in producing tomentums of some nature on almost all offspring of any hybrid cross. We have quite a number of hybrids from various seed lots. One other notable feature of the R. pachysanthum crosses is the very early bloom time. Bloom time here in Antigonish is usually around May20th, a week or more before many of the other large leaf rhodies bloom.
Three of our favourite R. pachysanthum crosses are 'Henry's Red' x R. pachysanthum, 'Janet Blair' x R. pachysanthum, and 'Calsap' x R. pachysanthum.

Leafy growth is the main feature of a couple of plants we have referred to as the "Bear Cubs". These are a cross of 'Teddy Bear' x R. rex. The tenderness of R. rex doesn't make it the most logical candidate for here in Northern N.S., but the 'Teddy Bear' parent seems to impart a necessary bit of hardiness. We were surprised by an actual flower on one of these plants this spring. Hopefully as the plant sets buds on the upper parts they will withstand winter!
They make quite large leaves, and have furry tomentum on the new leaf surfaces and along the stems.

"Bear Cub" tomentum 

Many seedlings give a hint at future performance , even when quite young. Some of the plants from 2008 seedlots are showing quite exuberant colouring on some of the new growth.

This 'Normandy' x R. calophytum cross will hopefully be an improvement on the species as we see it here. It seems to struggle just a bit, some years doing very well, others years not so well. Several of the R. calophytum species were grown by Bill and have found their way to ARHS members' gardens. It would be interesting to know how they are faring.
It is anyone's guess as to what may actually transpire at maturity, but colourful new leaves are enticing.

Last Day of March - First Garden Walk

We have finally been blessed with a nice, sunny, relatively warm day. I decided to try for a walk through part of the garden out back. It is still an interesting mix of snow and bare patches.
There is a lovely little patch of Crocus "Tricolour" blooming near the house.

I guess you could call this a "circle of sedum" along the path.

 The Octoberfest bed has a bit of one end bare so there were Crocus ancyrensis up and blooming there.

They are always the first to emerge as the snow retreats.They are brighter than bright!

The rhododendrons and azaleas are still very buried in snow in many places. This azalea is quite bent over. Hopefully it will spring back up when the snow leaves. I didn't look too closely to see whether there were broken branches.

These rhodies in the 2003 nursery bed and beyond are still basically buried. It would appear there may be almost 2 feet of snow in a few places. A walk in that direction can wait.

The potato pit also looks like it will need several more warm days before it could be accessed. We typically gain access during the first week of April(stay tuned!).

Some of the rhodies in the oak bed are looking very nice, and overall there doesn't appear to be any winter damage with respect to burnt leaves. This is a lovely indumented little plant grown from some no-ID seed . It is likely a R. pachysanthum cross.

Rhododendron 'Northern Starburst' is looking very good. Most of the center part of the Oak bed is bare, but still snow along the edges. Note there is a  teeny rhodie still surrounded. I expect that is one of John Weagle's diminutive crosses.

James is busy boiling down sap again today, after a bit of a hiatus due to several very cold days with negligable sap flow. Today and tomorrow ought to yield reasonable amounts.

Rhododendrons & Azaleas

We attended the Antigonish Garden Club meeting last Monday to give  a talk on Rhododendrons and Azaleas. We presented some of the varieties of both that are currently available to Atlantic gardeners, and added some information regarding cultural techniques.

Here are some of the salient features of the presentation taken as screen shots from Power Point. Look for several links to external images and for information files.

We presented several examples of rhododendrons that are early bloomers. One of the most common being 'PJM'.

We also introduced the species R. mucronulatum as the earliest bloomer (about the first of May most years). This semi-deciduous species is not readily available commercially, but we have grown many from seed over the years. They need a bit of publicity to become better known. They bloom in shades of pink/ mauve/purply shades as well as white.

This plant behaves much like a deciduous azalea, but is indeed a rhodie. The white version reminds one of a cloud of butterflies.

some of the other early bloomers mentioned included 'April Rose', 'Manitau', 'Ramapo', and 'Sue Gunn'.
Among the mid-late season bloomers presented were a mix of seedlings grown here and named varieties. One of those is affectionately known as "Sproeten".

"Sproeten" has a sister that we deem even more attrative. We have dubbed her "Ruby Lemon".

We have grown many seed lots over the years where the hybridizer aimed for yellow. This has been a bit of an elusive goal in many instances, especially for plants fully hardy in our zone. For a few more samples of seedlings have a look at this post.

Also of interest are the newer varieties of Finnish Hybrids that have become available in recent years.

Three of the most popular are below. To see a list of some available rhododendrons and azaleas here in Atlantic Canada follow the link.The list is a guideline and is in no way complete. Varieties will vary year to year and nursery to nursery.

 No discussion of rhododendrons grown here would be complete without some mention of some late-blooming varieties. These include several of the so-called "Ironclads", which have been a staple in gardens for many years.

Our personal favourite is the late blooming R. maximum hybrid 'Red River'.  It blooms in July well after the majority of others have finished.

The foliage aspect of rhododendrons is a great part of their beauty as garden plants. They help to give the garden year round interest.

Since foliage is an important  factor in rhododendron culture, we thought it important to point out some features.
Foliage is especially interesting at the "new growth" stage in spring and early summer.

Many types of rhododendrons exhibit foliage features associated with indumentum.This is a wooly feature on the underside of the leaf and sometimes on flower buds. It will usually persist for the life of the leaf. The leaf below left is from R. bureauvii.

Some species and hybrids also have a fuzzy coating on the new growth leaf surfaces called tomentum. It can be in shades of silvery gray to cinnamon. It will gradually wear away in the months to come. The image on the left below exhibits the "tomentum" on a R. pachysanthum hybrid.

Selecting plants that exhibit these features has been a goal of hybridizers over the years.
R. yakushimanum is the most prominent "donor" of such characteristics.

A few examples of "yak hybrids" are included below.

AZALEAS are just as popular here in our garden as rhododendrons and for the majority of gardeners a bit easier to manage. We often like to say they are a bit "idiot-proof"! This plant below is a pretty, fragrant azalea and is the first to bloom every year. It was grown from seed several years ago, but we have no idea of its origins. It also seems reluctant to set seed, so we haven't been able to get more. Some layering or cuttings will have to be attempted.

A few Azalea virtues.

Here are few examples of "variety"

In recent years there have been quite a large number of interesting azalea varieties introduced. Of these, those associated with the Northern Lights Series are some of the best.

The two examples above are just two of many.

Nurseries all over our area will have quite reasonable selections of this group of azaleas.You might like to check this article by Todd Boland.
No discussion of azaleas could omit our favourite....that being 'Homebush'. This is one of the most highly rated azaleas of all time and after many years of being difficult to find is now quite readily available.
It's distinctive ball-shaped truss and vigorous habit, make it a standout plant here in our garden.

Over the last few years we have been making an effort to choose azaleas that will extend the bloom period. There are several varieties available that are hybrids of late blooming native azaleas. Many of these will bloom well into July. 'Popsicle', 'Pennsylvania' and 'July Jester' are a few .

Included in the presentation was some discussion regarding successful cultivation of both Rhododendrons and Azaleas. 
A brief overview is below.

Everyone was given a reprint of the "bible" of Growing Rhododendrons in Atlantic Canada. All the information contained therein can be accessed from the Atlantic Rhododendron & Horticultural Soc website. Click the various links on the main page.
Thus endeth the lesson!