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

Tree Tobacco

nicotiana-glauca-foliage-640

 

Leathery steel-blue leaves, and on a plant you can grow as an annual, a perennial, a shrub, or a tree.  It's "tree" tobacco, Nicotiana glauca, a South American species that really is (at least in the subtropics) a small tree. 

 

You'll probably grow it as much or even more for the leaves than its arboreal aspirations:  They can be seven inches long and are on stems the exact same steel-blue color, too.  By August, you'll also have heavy clusters of pale-yellow flowers, complementary to the blue foliage if not exactly beautiful in their own right.  Hummingbirds think they're dandy. 

 

nicotiana-glauca-flower-cluster-64

 

Great leaves, interesting flowers—if only the plant itself were less of a gawky puzzle.  As an annual, it's corn-stalk vertical, and to twelve or fifteen feet.  Fun and easy, and then when frost comes, saw down the amazingly woody trunks and you're done for the season.

 

But Tree Tobacco really is woody and tree-like, at least in South America or California, so, of course, I have to experiment.  I need to grow it in a pot here in New England and, I must say, the jury's definitely still out. 

 

Yes, it has an, uh, interesting sparse canopy of weeping branches, each weighed down attractively by the large flower clusters. 

 

nicotiana-glauca-canopy-640

 

But the leaves aren't anywhere near seven inches, and I've somehow chosen to let the plant have a trunk that's six or seven feet tall.  The "tree" is still just a gangling sapling.

 

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In the garden in the Summer, in the greenhouse from November through early May.  And more pruning-back of the branches to get the canopy dense and proud?  Perhaps in a few more years my Tree Tobacco will look like a tree, not an anorexic?


Or maybe it really does want hot-and-dry climates, like this cliff-side planting on Italy's Amalfi Coast.

 

 

Here's how to grow this unusual blue tobacco:

 

Latin Name

Nicotiana glauca

Common Name

Tree Tobacco

Family

Solanaceae, the Potato family.

What kind of plant is it?

Subtropical evergreen tree.

Hardiness

In Zone 9, an upright large shrub or small tree; in Zone 8, a shorter and somewhat denser bush; in Zone 7, a returning perennial.  Everywhere else, a very large annual.

Habit

Single-trunked and, as an annual or in its first year or two, strongly upright.

Rate of Growth

The first season, or as an annual, extremely fast.

Size in ten years

A small tree to twelve or more feet tall and ten feet wide.

Texture

Sparsely-foliaged and open.  As an annual, a vertical dash of large steel-blue foliage.  As a returning perennial, multi-stemmed and open.  As a hardy shrub or small tree, few-branched and weedy-looking unless pinched or trained.

Grown for

its rarity: All the other ornamental and agricultural tobaccos are annuals or perennials.  Tree Tobacco is the only truly woody member of the family.

 

its foliage:  Tobacco foliage is typically light green, hairy, thin, and slightly sticky to the touch.  Nicotiana glauca is named for its glaucous—i.e., blue-green—leaves, which are smooth and thick, and can be as long as seven inches.  In my experience, the foliage is largest when Tree Tobacco is grown as an annual, but it's strikingly steel-blue at any size and on plants of any age.  

 

its size and scale as an annual: Tree Tobacco can soar to fourteen feet its first season, with a woody base four inches thick. 

 

its flowers: dense long-lasting clusters of narrow pale-yellow tubular flowers at the tips of the new growth.  They are a quirky but also stylish contrast with the foliage, and become large enough and heavy enough to make the branchlets arch down gracefully.  As is typical for flowers that are narrow and tubular, Tree Tobacco blossoms are much favored by hummingbirds.

Flowering season

Summer: June to frost.

Culture

As an annual, sun and any soil; tolerant of both rich and lean soils, but more vigorous with better soil.  Where hardy, full sun and soil that's very well-draining over the Winter, which always helps increase hardiness.

How to handle it

As an annual, you can sow seeds indoors a a month or two before the last frost.  Nicotiana all transplant well as young plants.  That said, with Tree Tobacco so much of the effect is from sheer size, so pot up seedlings as needed so they don't get pot-bound.  You want to encourage the plant to grow to maximum height before it starts to flower; if it senses restricted circumstances, it will start to flower prematurely (or at least pre-gigantically), and will put its energy into flowering instead of further height.

 

As an annual, Tree Tobacco would be sensational planted in "groves" in the midst of large beds.  The lower few feet of the trunk can become leafless and bare, so site your grove behind plants that will get three or four feet tall themselves over the season.  Ideally, the plants will get four or five yards tall by September, so give them all the space they need when planting: three feet apart is plenty close enough. 

 

Plant and grow as you would a dahlia: in full sun and in rich but fluffy and non-compacting soil.  Water if needed, but keep in mind that, like dahlias, these are plants native to hot and often dry locales in South America.  They like heat, and would prefer to have the soil surface get dusty-dry between waterings.

 

In Zone 7 and above, Tree Tobacco can be a woody member of your garden.  Mulch heavily in Zone 7, where you could grow the plant as a die-back shrub.  Pinch the new stems once or twice to help the plant get bushier; Tree Tobaccos tend to gawkiness. 

 

In truly mild climates—Zones 8 and above—where Tree Tobacco can grow large enough to live up (literally) to its "tree" name, experiment with pruning and pinching to get the canopy denser.  Maybe grow the plant as a single-trunked smaller ornamental tree; pollard each Spring—and pinch the new shoots once or even twice over the season.  Or cut (or saw) the limbs down to a foot or two in Spring, as you would a smoke bush. 

 

I'm experimenting with keeping a plant in a container year-round.

Downsides

Tobaccos are typically enthusiastic self-seeders, and the seeds can over-Winter even where the plants themselves are strictly tender.  Tree Tobacco is a common roadside weed in the Southwest, and is considered an invasive in California.  (I don't know if the seeds are hardy here in New England; next Spring I'll keep my eye out in the beds near where my potted Tree Tobacco summered.)  Pinch off flower clusters if self-seeding is a concern; the foliage is the real show for Tree Tobacco, and pinching will help the canopy dense-up, anyway.

 

Unless you grow it just as a "stunt annual," Tree Tobacco tends to be gawky and sparse.  You'll need to commit to regular pruning to have its branches and canopy become less awkward and open.

Variants

'Salta Blues' is supposed to be somewhat hardier, so more reliable in Zone 7.  There are several other Nicotiana species and cultivars to welcome into your garden.  N. alata has white flowers that, in the evening, become jasmine-scented.  N. langsdorphii has small green flowers, perfect for color-phobic sophisticates.  N. sylvestris has fragrant white flowers on tall "cobs," and can get six feet tall.  All of these can self-seed, gently or profusely; seedlings are easy to identify and, when necessary, yank.  Even smoking tobacco, N. tobacum, is a handsome ornamental in its own right, to seven feet tall with large sprays of white or pink flowers. 

Availability

On-line.

Propagation

By cuttings in Spring and Summer, or by seed.

Native habitat

Nicotiana glauca is native to South America.

 
 
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