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Rhododendron and
Azalea News

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Winter 2007  Vol. 10  No. 4
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A Maryland garden spot to visit

Editor Pat Kelly of the Mason-Dixon Chapter writes of a spot in Maryland that is worth visiting when traveling or you live nearby.  Put it on your “to see” list.

A surprising find on the ARS list of gardens and parks is...Garrett Park, Maryland.  Located north of Washington, D.C., it is a small town (0.3 square miles of land, with a population of 942) famous for its Victoria houses, trees, and shrubs.  The entire town is designated an arboretum, boasting more than 700 species of shrubs and trees, including a host of azaleas and rhododendrons.

Named for Robert W. Garrett, president of the Baltimore and Ohio Railroad, Garrett Park was laid out in 1887 along the lines of an English village.  Phil Normandy, a member of the Mason-Dixon Chapter, works part-time as Garrett Park's tree expert and cares for the 400 trees in the town’s public space.  Referring to majestic sugar maples that were planted shortly after the town was founded, Mr. Normandy says, "Trees get better with age and some of these are essentially antiques."

It would seem that Garrett Park is worth a visit...spring...summer...winter...or fall.


'Trilby'...hybrid for you to consider

Kathy Van Veen, of the Portland Chapter, writes: Truth be told, Daphne du Maurier is one of my favorite authors.  She may be familiar to you because of Rebecca.  Of particular interest to us is in that book the estate is called "Manderley"...and there is a bank of bright red rhododendrons near the house.  In 1969 a Dutch hybrid with bright red flowers was registered as 'Manderely'. For good reading, try du Maurier's, The House on the Strand...if you find it...that is.

Daphne's grandfather was George du Maurier and in 1892 he wrote a novel called, Trilby.  It concerns a young artist's model living in Paris.  Her name is Trilby O'Ferrall and she is romantically pursued by three art students.  One of these is William Bagot, or "Little Billie". Little Billie is especially attracted to her dainty little feet!  Keep this in mind; more about that later.

Little Billie proposes marriage 19 times and on the 20th Trilby accepts.  However, her mother convinces her not to do it.  Trilby then falls under the hypnotic influence of a man from Hungary called "Svengali" and becomes supposedly the greatest singer who ever lived.  But something bad happens.  At Trilby's public performance in England, Svengali has a heart attack...and dies.  Trilby loses her voice.  Sadly, she languishes...and dies. Kleenex please.

The rhododendron 'Trilby', in my father's words, is a dependable hybrid...with good habit and pleasing color.  It was registered by C. B. Van Ness before 1930 and has a distinctive foliage.  The leaves are stiff and have nice red petioles.  The flower is true red with a prominent maroon blotch.  Overall, the plant is vigorous, cold hardy, and sun tolerant.

Now, back to Trilby O'Ferrall.  The book was hugely popular on both sides of the Atlantic.  It was serialized in Harper's Magazine, was a popular stage production...and first appeared on film in 1927.  It could be said that the world was made for dear tragic Trilby O'Ferrall.  There were Trilby clubs, teas, hats, dances, and get this...tiny foot-shaped pins!

So, dear reader, if you are looking for that special, true red rhododendron for your garden, you may wish to follow Kathy's suggestion...add a 'Trilby'.


It's always something!

Norma Senn, of the Fraser South Chapter, has a treasure of information about your garden, rhododendrons, pests of the garden...and who knows what.  She always has an answer.  Listen to what you has to say this day.

Do you remember Gilda Radner, one of the original cast members on Saturday Night Live?  She had a great expression..."It's always something."

Well, at one of meetings, one of the members asked this question: What about Hosta Virus X?  I knew a little...but went searching on-line for some information about it and a couple of other new things that may cause problems...and, Gilda was right...there is always something!

Hosta Virus X  needs your attention...

Hosta Virus X (HVX) has been found in several northern U.S. states over the last few years...and is now known to be in Canada.  The extent of spread still isn't clearly understood...but HVX is thought to be very widespread.  We know there are certain Hosta varieties that definitely carry the virus and show specific symptoms.  However, here are also varieties that may be infected...but not show any symptoms.  We say the virus is masked.  And, then, there are some that may or may not be infected...and may or may not show symptoms.

viruses identified as "positive"...

As it turns out, some of the newer Hosta varieties that were selected for their beautiful yellow leaf markings are definitely virus infected.  In reading various websites, the variety names that keep popping up are:  ‘Breakdance’, ‘Eternal Father’, ‘Leopard Frog’, and ‘Lunacy’.  These varieties have all been confirmed “positive” for HVX...and it is the virus that causes leaf markings.

There are many other varieties that are suspected of being infected...but not yet confirmed.  For example, one of the most popular new Hosta varieties, ‘Sum and Substance’, is probably infected with HVX, and this particular variety has been widely sold throughout Europe and North America.  However, it still in not clear if all plants of ‘Sum and Substance’ are virus infected or not, so you may not necessarily have a potential problem if you plant this in your garden.

identifying signs...

If there are symptoms, HVX shows up as random mottling, distortion and/or crinkling of leaves, and the overall growth of infected plants can be poor.  Infected plants that have natural variegation tend to show a lot of mottling along the main veins.

However, just because a Hosta is variegated, doesn't necessarily mean that it is infected with HVX as not all variegated Hostas owe their leaf color patterns to the virus.  So, it can be tricky to decide if a plant is infected or not.  The only sure way to assess a given plant is to have it tested for virus by a plant pathologist...but this is a specialized and expensive undertaking.

valued advice on handling Hostas...

  At the moment it is thought that HVX is spread mechanically...when infected plant sap is moved to a healthy plants. This leads to a recommendation of being very careful when handling Hostas.
  • If cutting leaves or flowers or deadheading, wash pruning shears in a solution of bleach and water before moving on to another Hosta plant.
  • Shovels, digging forks, spades should also be carefully washed with bleach and water between plants when digging or dividing.
  • If you get sap on your hands when handling infected Hostas, you could spread the diseases to a healthy wash thoroughly between plants.
  • Don't use lawn mowers or weed eaters on or around Hostas at the end of the growing season to cut down spent this kind of equipment can spread the virus.
final solution...   If you suspect you have an infected plant in the garden, the recommendation dig the plant and place it in the garbage!  Hostas can have surprisingly large root systems, so make sure you remove all of the roots.  HVX cannot survive in the it is possible to re-plant another Hosta in the same location where one was removed as long as there are no pieces of root system left from the infected plant.



Daylily Gall Midge...needs attention, too...


The Daylily Gall Midge is definitely in the lower Mainland...that's America!  This tiny fly lays her eggs in the daylily flower buds.  After hatching, the larvae feed within the bud causing the flower bud to become swollen and distorted.  If you open one of the buds, you may see up to a couple of hundred tiny white larvae feeding...use a hand lens as the larvae are very small.  If left alone, the infested bud drops to the ground and the larvae are thought to pupate in the soil over winter.

  • One relatively easy control method is to patrol your daylilies frequently and physically remove all flower buds that look abnormal in any way.
  • Put the buds in the garbage.
  • Do not compost them or leave them lying on the ground.
  • It seems that the adult midge is particularly attracted to early yellow daylily varieties, so you may want to avoid growing these types.
  • Yellow sticky traps can be mounted on small stakes and placed around your daylilies to trap some of the adults.

Pam Erickson has written a more detailed article about Daylily Gall Midge that includes some pictures of infested buds.  The article is at

Daylily rust...


Daylily rust is the third example of: "it's always something,"...Daylily rust has been found in Ontario, so it could be just a matter of time before it shows up in other gardens.

Daylily rust looks likes like a typical rust infection: leaves will have small raised areas of rusty yellow pustules on the leaves or flower stalks.  After infection, the infected leaf tissue becomes progressively chlorotic.

As is the case with other rusts, this fungus alternates between two hot this case, daylily and Patrinia (Golden Valerian).  We don't grow Patrinia very often locally (I had to look up the plant as it was a new genus to me), so this should help us keep daylily rust in check...if it does finally show up.  However, it may be that part of the rust cycle can be completed by living on any daylily foliage that over-winters in our area.

  • This leads to a control recommendation of cutting back the foliage in the fall so that no green leaf tissue remains.
  • Do not mulch plants for winter protection as the mulch may protect rust pustules present at the leaf/root junction.
  • Plants should be divided and spaced out regularly to provide good air circulation.
  • Do not grow any Patrinia species near daylilies and, when watering, avoid overhead irrigation...or if watering with a sprinkler, do this early in the day so the foliage dries out quickly.
  • Rust spore germination and infection is favored by having foliage continuously wet for 5 to 6 hours and temperatures of 22 to 24C.

There is an excellent site with information about this rust (Puccinia hemerrocallidis) at

In addition to these three problems, there are other new pests, too: Sudden Oak Death, European Chafer Beetle, and Viburnum Leaf Beetle immediately come to mind. Sad to say, but..."It's always something!"


Companion plant...Weigela  

Once the main splash of rhododendrons is over...there is a charming group of plants that fills the color gaps in our landscapes quite nicely.  Named after a German botanist, C. E. von Weigel, the Cardinal Flowers (zone 4/5) are deciduous shrubs of open woodland areas in parts of Asia, which have a multitude of foliage and flower features.

want hummingbirds by the flock...

  Most of our available varieties are selections of hybrids of two species: W. flordia and W. praecox, although the wild forms are rarely offered.  The blooms, in May and June, are tubular, in small clusters along older stems, often with nicely contrasting stamens.  In blossom, they attract hummingbirds by the flock!

the "in"  plant...purple leaves

  The "in" thing these days among plant introducers is...purple leaves, starting back with 'Foliis Purpureis' ('Jave Red'), on to 'Victoria', then 'Wine and Roses' ('Alexandra'), 'Ruby Queen', and now...'Midnight Wine'!  The color is getting darker, and the plant habit is getting smaller...what's next...a black groundcover Weigela?  Attractive and useful plants...nevertheless...most of them have pink to bright pink blossoms.

The 'Dance Series'...developed by Agriculture Canada...have all been selected for very compact habits, extra hardiness (zone 4), and richly colored blooms.  Foliage variations are from green to burgundy, with deep pink or red blooms.  Look for 'Tango', 'Polka', 'Samba', 'Rumba', and 'Minuet'.

gold-leafed forms are...finicky...   Gold-leafed forms are a bit more finicky...they need partial shade to avoid foliage burn...but too much shade makes them go it is a fine line. 'Looymansii Auarea' has pale pink blooms...while the newer 'Briant Rubidor' (aka 'Olympiade' or 'Golden Ruby') dark ruby flowers that offer a striking contrast.  Variegated leaves, with cream to light yellow margins, occur in both species, and have pink flowers.  The variegated areas take on rich pink to red tones in fall...for extra punch.

white-flowered forms available, too...

  White-flowered forms are available as 'Bristol Snowflake', 'Candida', 'Mont Blanc', and others...but I must admit I don't really care for them...although 'Mont Blanc' is highly rated.  Possibly, I just haven't seen one at the right stage...or in the right setting.  A new introduction, 'Carnaval', has blooms of white and two shades of pink all at once on the same plant.  That's kind of neat!

For deep reds, the old 'Bristol Ruby' and 'Eva Rathke'...although good and reliable...have been superseded by newer, tidier, non-fading varieties like 'Red Prince', 'Lucifer', and the even smaller 'Nain Rouge'.

growing conditions…   Weigelas grow easily in any well-drained moderate soil...and old bloomed-out stems can be cut to the ground to allow new ones to take their place.  Trim right after blossoming in the early summer to keep leggy branches in order...and to give time for the wood to ripen and set bloom for the next year.  Some varieties will bloom off and on throughout the summer, and others appear in early summer...and again in early fall.

Two unusual species, W. middendorffiana and W. maximowiczii, have light yellow flowers in late spring...most "un-weigela-like" but...truthfully...I have not seen either offered for sale Canada.  Good on you...if you can find one.

Look around din the plant centers when you have gotten all your beddings settled and your rhodos are on the wane...and you will find one of these to be a delightful addition to your garden...big or small.

Happy Planting!

Colleen Forster, Fraser South Chapter


Shade, shade, and shade

  Harry Wright, of the North Island Chapter, delights in writing and sharing his knowledge of rhododendrons, azaleas, companion plants and many other things.  He wrote an interesting article...especially for winter when there is less shade...but you might be thinking about more summer shade for your rhodos.

Shade, shade, shade...seems that every garden I enter, the topic of shade is mentioned at least once.  Not enough shade...too much shade...a new garden does not have enough...and older gardens have too much shade.

  • A plant...when small and planted near light shade...seems too soon to be located in the wrong area once the shade canopy has increased.
  • With shade available, a greater selection of plants can be enjoyed...and they can only be enjoyed...if they are grown in their chosen environment...sunny or shady location.  Trees provide shade...finer-leaved trees will provide filtered shade and larger-leafed ones create dense shade.  Degrees of shade can be controlled by proper placement of plant material...and, if anyone has the privilege of creating a new garden, afternoon shade can be directed by planting a tree 10 ft. south and 10 ft. west of the target area.
  • When selecting trees, we should be concerned about the type of root system as this could restrict the planting area available around trees.  Trees with a tap-root system would be preferred.
  • Gleditsia trriacanthos 'Sunburst' locust would be a good choice for a large tree.  The foliage is bright yellow, and the fact that it leafs out late in spring allows the ground to warm up.  By the time the weather gets hot, the tree is providing light-filtered shade.
  • My choice for a smaller tree would be a Styrax japonica.  Flowers are waxy, white, fragrant, bell-shaped, about " long, blooming mid-June...after most other trees have finished blooming.  Small leaves allow light shade.
  • Evergreen trees are also good providers of shade...with many colors of green, blue, and yellow to choose from...but most evergreens have surface roots, making it difficult to plant under them.
  • Hedging can also be used to create well as fencing.  If instant shade is required, a section of fencing can be used...and removed at a later date when the tree canopy has been developed.
  • If existing trees are causing too much shade, it is time to start removing some lower branches.  I have been told that as a tree grows higher, the existing branches will be higher from the ground...wrong!  If that was the case, we would be lowering our swings...continually.
  • Low branches will always cause more the longer they get, the heavier...thus, causing them to droop more, increasing the shade.

Final thought: Trees should be looked at...walked under...not around.


Something to ponder...


A gardener's work is never at an end;
it begins with the year,
and continues to the next;
he prepares the ground,
and then he sows it;
after that he plants, and
then he gathers the fruits.

-- Evelyn Kalendarium Hortense 1706

Presented in the Eugene Chapter News, December 2007


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