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

The Best Season Ever: Fall Colors of Switch Grass

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Switch grass is justly famous for cultivars, such as 'Dallas Blues', with steel-blue foliage. Uniquely, 'Dallas Blues' pairs that color with seeds that are rosy-pink. In August, the grass is a perfection of pastels.

 

By early November, both the foliage and the seeds have shifted to shades of chocolate. The look is sophisticated and also, handily, coordinates well with neighbors whose Fall color might otherwise be dismissed as merely brown.

 

The dark burgundy of new stems of Hydrangea paniculata 'Pink Diamond' is a lucky match. Less so are the petal-free flowers of Boltonia 'Nally's Lime Dots', which have changed from their August shade of green to a buff that has too much yellow in it.

 

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The hydrangea's flowers are in sync from the moment they emerge (creamy), through adulthood (rosy pink), and into their current dried antiquity (parchment and brown).

 

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Here's how to grow this exceptional switch grass:

 

Latin name

Panicum virgatum 'Dallas Blues'

Common name

Dallas Blues switch grass

Family

Poaceae, the Grass family.

What kind of plant is it

Perennial grass.

Hardiness

Zones 4 to 9.

Habit

Clumping but not static; colonies diligently expand by about (for me) a foot in diameter annually. The distinctly upright leaf stems have long and gently-arching leaf blades. The stems terminate in delightfully airy panicles whose branching is so wide and profuse, and whose numbers are so great overall, that they meld into one cloud-like mass of small seeds floating amid the upper reaches of the foliage, as well as atop the entire clump.   

Rate of growth

Fast but not alarming.

Size in ten years

In my experience, clumps need division every three or four years, at which time they can be four feet across and five to six feet tall at their August through October peak.

Texture

Gracefully vertical and, well, grassy in foliage; when the delicately-branched and seeded panicles appear, topped with a cloud.

Grown for

its foliage: Tall upright stems bear long blue curving leaf blades that are steel blue in Summer. In Fall, the blades turn milk-chocolate.

 

its panicles: Airy and bearing a profuse crop of rosy-pink seeds, these bring an entirely different color after they appear in August. In Fall, they change to a tan that is without yellow—the color of diluted chocolate milk—that coordinates masterfully with the deeper chocolate of the leaf blades.

 

its vigor: Panicum will grow just about anywhere it can receive full sun, and it will persist indefinitely. In my experience, clumps open up at the center as the periphery spreads outward. See "How to handle it."

 

its imperviousness to browsers:  As is typical for ornamental grasses, Panicum is not usually of interest to typical garden browsers such as deer or rabbits. It is readily cropped by cows, though, and, indeed, can be used as hay or forage.

Flowering season

Late Summer: August through Fall. 

Color combinations

Rosy-pink panicles and steel-blue foliage: If ever a grass were perfect for baby-doll pastels and burgundy, 'Dallas Blues' is it. Avoid siting near yellow, orange, or red.

Partner plants

Mix grasses with larger-foliaged partners or, at least, partners whose foliage, in any size, is comparatively rounded instead of long and narrow. The exciting August and September peak of 'Dallas Blues' would be wasted amid partners that look tired in late Summer. The grass is more the best-ever filler instead of the starring focus, so it needs at least one neighbor that is a reliable star in high Summer. As long as they are all sited so as not to cast shade onto 'Dallas Blues', consider shrubs and small trees with rounded purple foliage: Cotinus coggygria 'Velvet Cloak', Physocarpus opulifolius 'Summer Wine', and Cercis canadensis 'Merlot' are all hardy to Zone 5. If you have a tall-enough container specimen of Euphorbia cotinifolia (which is hardy only to Zone 9), set it so the billowing mass of 'Dallas Blues' laps at the bottom of its canopy. (Note to self: Pots of Euphorbia continifolia in the garden in 2013, please!)

 

Late-season hydrangeas are fool-proof. The flowers of most H. paniculata cultivars peak at the same time as the panicles of 'Dallas Blues', and also last every bit as long into Fall, getting pinker and pinker until, as in the pictures above, there's a switch to shades of chocolate. I've paired my 'Dallas Blues' with H. paniculata 'Pink Diamond'. Although the flowers of H. quercifolia open much earlier in the season, they are in peak pinkness when panicles of 'Dallas Blues' emerge. And they, too, last through the Fall. 

Where to use it in your garden

Unless you site 'Dallas Blues' in drier soil, in which is it less likely to flop, this is not the ornamental grass to use in quantity. The verticality of the growth is only relative, not dogmatic, as is the case with, say, Calamagrostis acutiflora 'Stricta'. So clumps aren't at their best when sited in isolation, to be seen head-to-toe. Happily, that same casual verticality makes 'Dallas Blues' all the easier to use in the midst of larger plantings, where grasses that "fountain" can swamp neighbors, and grasses that are too narrowly columnar might become lost. Provided you stake (see "How to handle it: Another option—or two!"), the footprint of a clump of 'Dallas Blues' in Spring is about the same as the diameter of the full-force growth in August.

Culture

Full sun. Panicum cultivars thrive in almost any soil, rich or poor, with almost any amount of soil moisture.

How to handle it: The Basics

As is typical for ornamental grasses, plant in Spring. Panicum roots grow to extraordinary depth—the rule of thumb is that they grow down as far as the stems and panicles reach up—so clumps quickly become completely self-sufficient.

 

Panicum might self-seed where you garden; check with the local office of the USDA Cooperative Extension Service. If self-seeding is a concern, cut the stems down to six inches as soon as you can bear after the clump has taken on its Fall coloring. If self-seeding is not a concern—I have never noticed volunteers in my own gardens here in New England, e.g.—cut old stems down to six inches anytime that's convenient from late Fall to late Winter. Be sure to harvest the old growth before new growth begins to emerge in Spring.

 

Clumps definitely increase in width, and thin at the center just as reliably. Every three or four years, dig up the entire clump in early Spring when new growth has just begun, and replant some of the peripheral sections to reconstitute a clump of the width you need. Despite its famously deep roots, Panicum is an easy dig, at least when compared with such notoriously difficult-to-dig species with thicker stems and taller habits as Miscanthus and Arundo. Even so, if you need to dig up ornamental grasses more than once a year, you'll appreciate having invested in a spade with a long but narrow blade, and of as heavy construction as you can find or afford. Also, buy one with treads, which means that the upper edge of the blade is widened so that you can stand on it, or even jump onto it with your full weight, when the spade needs extra force to pierce deeper roots. These are often called rabbiting spades, because they reach deep enough (so I read) to dig into rabbit burrows. 

How to handle it: Another option—or two?

Unless it's sited in drier soils, 'Dallas Blues' tends to flop just as it nears its ravishing peak of volume in August, when that one gully-washer storm will cause the clump to look like a giant stepped on it. After-the-fact staking inevitably makes the clump look like it's being taken hostage. The clump maintains its verticality right until the day of disaster so, even well into the growing season, you can access it easily for proactive staking.

 

Pound in three or four tomato stakes right into the periphery of the clump, and one right in the center. Tie twine stake-to-stake around the periphery. Then tie across them, looping around the center stake so that the peripheral stakes aren't pulled inward, to segment the mass of Panicum stems into pie-shaped segments. If the tops of the peripheral stakes are four feet, they'll be high enough to support the stems but not so high as to interfere with the cloud-like effect of the panicles. If you want, make the center stake a bit taller still, to help maximize the colony's storm-proof height.

 

As with staking cardoons, if you can use stakes that are handsome in themselves, and you can pound them so their tops are at the same height, they can be a part of the ornamental look of the colony. If you use stakes of wood, start with new ones each year. Wood stakes need to be removed in Fall, otherwise they'll rot substantially over the Winter. To spare yourself the annual task of pounding in the stakes in mid-Summer, then yanking them out in late Fall, consider installing a set of six-foot length lengths of rebar. They'll last for many years.

Any (other) quirks or special cases?

None.

Downsides

Deep soil and plentiful water ensure the tallest growth, but also the certain need for staking.

Variants

Panicum cultivars vary chiefly by height and panicle color. 'Cloud Nine' can grow to 8 or 9 feet, with light blue foliage and golden yellow panicles. 'Heavy Metal' grows 4 to 5 feet, with blue foliage and panicles that are buff. 'Rotstrahlbusch' grows to 3 feet; its foliage turns red in the Fall, and its panicles are burgundy. 'Squaw' grows 3 to 4 feet, with green foliage (turning red in Fall) and pink panicles. To date, 'Dallas Blues' is the only cultivar with blue foliage and pink panicles. 

 

Availability

On-line.

Propagation

By division.

Native habitat

Panicum virgatum is native to central North America from Canada to Mexico. 'Dallas Blues' was first noticed in Dallas, Texas.

 
 
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