Factors that determines coleus color
I was given a Coleus cutting which I further divided to start about six small plants. I never actually saw the parent plant (other than this cutting) so didn't know exactly what I should expect.
I potted them, not in commercial potting soil but in my own mix (compost, vermicompost, soil, etc). I also included some ground eggshells because I read that Coleus prefer less acidic soil.
All cuttings were successful and I eventually had several, apparently, healthy plants. I later transferred two of them into different containers my girlfriend had earlier filled withÂI thinkÂ a commercial potting mix. In a week or less, those two plants were a deep dark plum/purple while the others remained a somewhat faded green with tinges of pink here and there.
All plants are from the same cutting from the same plant, receive about the same amount of moisture and sun. (If anything, the two more colorful plants may be receiving slightly more sun even though my understanding is that less sun develops deeper colours). The only significant difference is the soil itself.
(I am now experimenting with the others but in the meantime) what is it that accounts for such a dramatic coloration difference?
The soil ph? Higher level of Nitrogen, Phosphorous, Potassium or Micro-nutrient? individually or in combination?
Previously, I had thought it was the amount of sun/shade alone that effected the depth of color in Coleus. Obviously it's something more ..but what?