Louis Raymond experiments in his own gardens like

a mad scientist, searching out plants that most people have

never seen before & figuring out how to make them perform.- The Boston Globe

…Louis Raymond ensures that trees can grow in Brooklyn…

or just about any other place where concrete consumes

the dirt and skyscrapers shield the sunshine.- USA Today

 
 

NEW Trips to Take!

Myrtle's easy when the conditions are right.

 
 
 
 

NEW Plants to Try!

Louis tries to capture the exact words to describe the fleeting but deep pleasures to be found in these Summer-into-Autumn incredibles.

 
 
 
 

New Gardening to Do!

Allergic to bees? You can still have an exciting garden, full of flowers and color and wildlife.

 
 
 
 

Plant Profiles

Blue-leaved Himalayan Musk Rose

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A Himalayan musk rose in bloom in New England? This species is a bit tender colder than Zone 7 so, yes, there's a trick: I keep the pot in the greenhouse. For flowers and—even more so—the blue foliage, this rose is worth just about any amount of fussing.

 

'La Mortola' is the musk rose cultivar to grow: huge foliage, fragrant flowers, and growth to thirty feet.  (To thirty feet, that is, when it's happy.  The rose and me, we're working on it together.) 

 

But even if flowering is sparse, there's the foliage.  Right up there with the other blue-leaved rose, R. glauca, Rosa brunonii 'La Mortola' would be worth it even without its delicious flowers.

 

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The elegant pointed leaflets occur almost always in sevens.  They're an exciting slate blue that is only more telling for arising from burgundy leaf-stems and pink-blue stems.  Ah, if only I had another hundred yards of high and perfect (some day) yew hedging, the perfect dark backdrop for this remarkable climber.  

 

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But it's not really hardy here, so my 'La Mortola' will always be in a pot.  See "How to Handle It" below for my strategy to grow this rose into a huge and heavily-flowering triumph—

 

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—but one I can still move in and out of the greenhouse. 

 

Here's how to grow this elegant beauty:

Latin Name

Rosa brunonii 'La Mortola'

Common Name

'La Mortola' rose

Family

Rosaceae, the Rose family.

What kind of plant is it?

Climbing rose.

Hardiness

Zones 6b - 9b

Habit

Very long canes with sparse downward-pointing thorns that enable the shrub to climb easily up into trees.  Potentially a massive but always graceful plant.

Rate of Growth

Fast when happy.  So far, my own individual has been slow-growing; I need to make it happier!

Size in ten years

Canes can lengthen to 30 feet in a climate a lot milder than mine—Zone 8, say, where it wouldn't get die-back over the Winter—for a conceivable spread of sixty feet wide and thirty feet tall.

Texture

Elegant even just in leaf:  The willowy foliage is unusually large, narrow, and blue, and is widely-held in septets on burgundy stems.  Large clusters of single white flowers are a thrilling but only-once-a-year bounty.

Grown for

the foliage: As in "Texture" above, the foliage is strikingly blue, with septets of elegantly narrow leaflets spaciously arrayed on burgundy stems.  'La Mortola' would be grown even if it never flowered.   

 

its flowers: Five-petaled, single and white, intensely fragrant, and in large clusters.  A large specimen of 'La Mortola' in bloom must be a riveting experience.  Flowering is once a year only, though, for only about two weeks, but (to my eye and nose) this only enhances their desirability.  

 

its habit:  The very long and flexible canes are easy to train onto large pergolas or up into medium or even large trees.

 

its rarity: if 'La Mortola' were readily available, it would be damned by familiarity the same way that agapanthus are:  Growing by the millions in California, they're eschewed by sophisticates there.  But their rarity on the East Coast automatically elevates them to swooning desirability.

Flowering season

In milder climates where the rose isn't set back by rough Winter weather, starting into bloom any time from April to July depending on how long the (mild) Winter is; flowering is for only about two weeks.

Culture

Full sun and decent-to-rich soil.  As always, good drainage is essential for maximal hardiness.  Growth is faster in plusher circumstances, especially where the stems are sheltered during the Winter.

How to handle it

In Zone 8 and 9, plant in deeply-cultivated rich soil in sun or even part shade, water deeply during drought, train the quickly-lengthening canes regularly, and in only a few years you can expect to have coverage of even large structures or growth to the top of large trees. 

 

In Zone 7, siting to provide all possible Winter shelter is key.  Can the plant be grown against a west-facing wall?  Even better, could it be grown against a west-facing wall with a bit of roof overhang but also full exposure to the full extent of afternoon-to-dusk sun?  The overhang would help shunt cold air out away from the canes, while the fullest amount of western sun would ripen the canes as much as possible.

 

Being once-blooming, and doing so early in the season, this rose blooms at the tips of new growth arising from stems that overwintered successfully.  Substantial winter die-back—let alone to-the-ground die-back—precludes flowering, even though the bush will still resprout with new stems.  Below Zone 7, the stems aren't reliably Winter-hardy, and so if it's to bloom 'La Mortola' will need to be grown in a pot that's brought into shelter.  

 

I let my potted plant get a few whiffs of frost each Fall, so it sheds its leaves and goes dormant.  Then I store it in the basement for the Winter.  Even though the overwintering is frost-free, growth is slow to resume in Spring, and flowering is very sparse.  I'm hoping I'll have more success by sheltering the plant in the greenhouse instead, where it can stay in leaf all Winter and therefore, at least moderately, also in growth.  With a much shallower dormancy, then, the return to full Summer horsepower should be quicker and more sustained.

 

'La Mortola' can be evergreen in mild climates, and where Winter survival of stems isn't a concern the shrub can be pruned as needed.  In chancier climates, pruning should be limited to right after flowering, so new growth can increase as well as harden-off to the max before the next bout of potentially damaging cold weather returns.  

 

You may well ask how a rose that blooms on wood that must survive from the previous year, but can also get thirty feet long, could be handled, literally, when being pot-grown in a climate where that pot must shuttle into shelter from November to late April, and back outside from May through October.  Even for a plant geek, there must be practical limits.  How big a plant can be grown in a given pot?  How long can the canes get without making the plant too awkward to maneuver?  Can they be gently looped or doubled back on themselves so the plant stays within the dimensions of plausible movability?  

 

One solution will be to grow the bush as a spiral around a tuteur.  If I'm able to grow stems of only ten feet long, they can spiral up to the top of the tuteur more steeply.  If stems want to grow to twenty feet, though, I can retie the lot of them so their spiralling ascent is at a much slower pace.

Downsides

If only it were hardier.

Variants

Rosa brunonii 'La Mortola' has such exceptionally blue foliage and comparatively large flowers that it supersedes the straight species.  'Betty Sherriff' has pink flowers and foliage that is dark green; for my money 'La Mortola' is the more distinctive plant. 

Availability

On-line.

Propagation

By grafting or cuttings.  

Native habitat

Rosa brunonii is native to China, and was introduced to Europe in 1822.  'La Mortola' was identified in the south of France in 1954.   

 
 
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