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

Hardy Persian Shield



Blue flowers.  Well, blue-ish flowers.  In August and September, we'll take all of them.  Hardy Persian Shield looks like its cousin, the big blue salvias, but if the nurseries are to be believed, it's a whole lot hardier: To Boston or even Maine.  I'll know if it's even hardy to Zone 6 when I welcome my plants to their second Summer in 2012. 


Meanwhile, it's a delicate partner to the gold arborvitae in the back and—if they ever come into bloom—pale yellow 'Honka' dahlias out of frame to the right.




Stay tuned.



Here's how to grow this unusual blue-flowered perennial:


Latin Name

Strobilanthes atropurpureus

Common Name

Hardy Persian Shield


Acanthaceae, the Acanthus family.

What kind of plant is it?

Hardy flowering perennial.


Zones 4? 5? 6 - 9.


Upright and shrubby.

Rate of Growth


Size in ten years

A clump to four feet tall and three feet wide.


The green foliage is large and plain, and dense enough for this large perennial to act like a shrub in your August garden.  The delicate flowers float gracefully above the foliage on many-branched stems that have few leaves.

Grown for

its rarity: Persian Shield is a popular annual north of Zone 10, and is grown for its metallic purple leaves and vigorous growth to four feet and more.  The flowers are, at best, an afterthought.  It's quite a surprise to have a Persian Shield with (honestly) boring green leaves, showy flowers, and hardiness to Maine. 


its flowers, which are (despite how they often photograph) deep blue-purple. 

Flowering season

Summer: July into September.


Part shade all day, or shade in the afternoon, and rich well-drained soil.

How to handle it

I'm in my first season with Strobilanthes.  So far, so good.  The plant is quick and sub-shrubby just like its Salvia relatives, and should be  a welcome oddity in any garden where it's hardy. 


It's so new to North American gardening, though, that its hardiness is still being confirmed.  One supplier rates it only as a mild Zone 6, another a deep-freeze Zone 4.  It's probably wisest, then, to do everything you can to help it survive the cold months: Don't cut down the dead stems until Spring, grow it in a bed that's mounded higher than its surroundings so it's assured great Winter drainage, and mulch it well the first Winter or two.

Because the flowering is in high Summer and early Fall at the tips of every new stem, you could pinch the stem tips in May or June for an even bushier plant and an even more floriferous display.  On the other hand, unpinched plants will be somewhat taller, which has its own appeal.


Strobilanthes expands the potential spots for which you can create a Salvia-like cloud of small tubular Summer flowers, because while Salvia worship the sun, Strobilanthes will scorch unless it gets a bit of shade.


With such a long season of bloom—and in a deep blue that goes as well with pale pinks as it does vermillions and chrome—it looks good with everything.  I'm growing mine in what will, someday, be that necessary afternoon shade, from yellow arborvitae that I'm training, trunks and all, into spirals.  Near-term, the Strobilanthes are almost as big as the arbovitae, so their foliage has gotten a bit bleached by hot Summer sun.


None I've discovered yet.


Strobilanthes dyerianus is the popular metalic-purple foliage plant for hot-weather color.  Although there are several dozen other Strobilanthes, none—yet—have been welcomed into gardens. 




By division in Spring, or by seed.

Native habitat

Strobilanthes is native to the Himalayas.

FacebookTwitterRSS Feed

Stay in touch!


Sign up for twice-monthly eNews, plus notification of new posts:


* indicates required