Contrary to most of what I've read and experienced growing Salvia D, is that they abhor sun light. At least in Northern California, the sun burns them inhibiting growth and overall health.
If we think of their natural environment, ravines in high mountain ranges of Oaxaca, Mexico- we can imagine a hot and dark climate. Quoting from Daniel Sieberts page, they were often found in hard to get places and were then transported by humans to a more desirable place to garden.
In Northern California where they reside in a greenhouse, we must put a 70% shade cloth over our plants or our they will burn and not grow properly. Shade cloths are woven plastic that don't allow full sun on your plants. There are numerous percentages- from 10-90% shade clothes- there are many options for growing conditions to make a perfect home for your own salvia d.
In an environment where they can grow in almost full shade, I have noticed leaves that were quite large- 6-7" long and 4-" wide with full sized square stems. Without enough shade in the summer, leaves are barely 3.5" long and 1.5" wide. This leaf size was with 60% shade cloth ( 3 -20% shade cloths on top of the greehouse). I do think, however, that one shade cloth of 60% shade would be a lot more successful than the previous method.
And almost as important as lack of sun for upward successful growth of your Salvia D plants, is the medium in which their roots are situated. Through all my years of growing this mystical plant I have finally learned they want nothing more than peat moss, maybe some pearlite, MAYBE some vermiculite, but otherwise- peat moss, peat moss, peat moss. I do not of course claim this to be the utmost dirt medium to aid Salvia D in growing properly, but it is the only medium I have found that doesn't kill Salvia d completely. I have also found a healthy top dressing of peat moss on your already full pot of peat moss aids the plant with fresh acidic ph for its soil.
But like I say, I have only grown this plant in Northern California. The conditions around the continental US are quite different- from tropical Florida, to chilly Wyoming. But how about the summers? and spring? And I have heard that in Hawaii the plant is quite successful, as is most any other plant that thrives on perfect humidity, temperature, soil etc.
I have always recommended that any person thinking about growing this plant to think about the shadiest, warmest, watery place they could imagine in or outside their home. Of course this is thinking of high summer and not high winter.
Salvia D can survive down to freezing, although I have not tested this in the ground. And growth, of course, is slow if not nonexistent at 0 degrees. Salvia D will grow slowly at temperatures (in a greenhouse) of 20 degrees with full sun in the daytime with daytime temperatures of 40-60 degrees.
I cannot imagine Salvia D surviving more than one winter in the ground outside with freeze or frost on the ground. I have heard of sucessful garden growth with slight frost but the plant only lasted two years (with growth up to 8 ft in summer). This account was from Oakland, Ca. I could see one scenario working but these are for winters in mild winter climates, cutting down the plant in fall after it flowers. Cutting the plant to just above ground level, with at least four sets of leaves (or the gardener can lay down these shoots under the ground to ensure next years growth- the stem will root in the ground). After cutting down the plant, mulching with wood chips, straw, peat moss, (one or all) and if conditions were more than mild cusping on severe, one could make a hasty lettuce greenhouse with pvc pipe and white plastic of any grade. (I've used grocery white plastic before to make cuttings.) If one were vigilant enough to mulch and protect Salvia D if a frost was coming, growth for the next spring could be ensured.
Otherwise in winter I would suggest an indoor setting or a pot for outside, near or on a covered patio. With the grey skies of winter, any window would be fine for Salvia D.
You'll know your plant is getting to much sun when leaf size and stem are small as well as severe yellowing- your salvia d plant should have dark green leaves. Salvia D, like its psychoactive cousins Psychotria and Yage, they are canopy plants meaning they grow in the shade of much larger plants or trees. The vine Yage will grow to the top of the tree its winding itself on, flower through the canopy, the flower dies, and it retracts back to the ground. And back up again.
So think of dark, think of shade, think of hot and peat moss, and you have a generall success rate for your Salvia D.
