True blue, rare in flowers, is easily obtainable in bog sage

There are gardeners among us who are thrown into a swoon that even Elvis couldn’t offer over blue flowers. These are (usually) the elite, the cognoscenti of the horticultural world, if you will, who have risen above red and orange. Or at least ones that fancy themselves such.
I am not one of the above, but often suffer the same effect over blue. On the face of it, there would seem to be plenty of blue flowers to choose from but, alas, that is not the case.
Ersatz blues there are aplenty. Most of them are really mauve, violet, lavender, purple, or something in between, even sometimes bordering on pink. All of these are mistakenly lumped into “blue.”
There are precious few true blue flowers; that is, unsullied with one of those mentioned other shades. One pure blue coming to mind is Salvia uliginosa.
Hold a spire of its flowers (they run to spires) against a clear summer sky and you will find they are exactly the same color.
I have mentioned this excellent perennial before, but only as a peripheral note. Now let us take it on in earnest.
My patches of it are all descended from a gift plant. The benefactors were Neil and Kitty Taylor of Collierville, who had (they have now downsized) one of the great gardens in the Memphis area, on the periphery of Collierville.
I remember their marvelous double English borders and a sizeable rock garden at the front drive.
Kitty was for years a notable garden designer in the area and we met the Taylors on our first British garden tour.
Neil referred to the salvia as “old ugly nose,” no doubt in reference to the specific epithet.
Whatever. The more common name is bog sage, though it certainly needs no bog to thrive. In fact, I have two sizeable stands at our driveway that receive no irrigation, yet even in drought years (i.e. this one) it never blinks.
The big caveat with bog sage is its aggressiveness. It will run at the root with alarming efficiency, and I would warn against introducing it into polite company.
In other instances, however, this spreading tendency is an advantage.
The two aforementioned patches at our drive are ensconced amongst such stalwarts as spreading junipers, big waist-high hollies, winter jasmine and nandinas. No problem.
Bog sage thrusts itself up through it all and begins producing its flowers on four-foot stems by June.
In November it had reached six or seven feet and never had slacked a bit in flowering. Six months’ performance for any perennial is almost unheard-of.
Those tall stems are a bit wobbly, and unless supported by other plants (or staking) are apt to flop. If whacked back by half in, say, July (which you will be loath to do while it is in full bloom), the height can be controlled a bit. Flowering will slack for a few weeks.
The loose spires of bog sage range up to eight inches long. New flowers are produced on and on, ahead of trailing calyxes of gray and white, which add their own little contribution.
Forget manure, artificial fertilizer or any other elixer. Bog sage subsists on virtually no amendments as long as the ground is  average or even somewhat less.
Bog sage is seldom seen in nurseries and garden centers. It runs up quite a bit of stem before blooming, and thus is not a very salable subject for those gardeners (most of them) who are unfamiliar with it.
So beg a root or two from a fellow gardener, plant it in full sun, sit back and enjoy one of the truest blues in the flower world.
From Poor Willie’s Almanack: “I got the bog sage blues!”
Editor’s note: Jimmy Williams is the garden writer at The Paris Post-Intelligencer, where he can be contacted on Mondays at (731) 642-1162.

Published in The Messenger 12.18.12

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