I have petunia volunteers too. Some come back as they were,
but the one in my profile album came back yellow with lavendar edges! It is the second pic on page 1.
The purple wave is slow...mine too.
I found that the Super Blossom fertilizer just totally ramped up my toonies last summer. 10-52-10 very powerful. I mix it very dilute, and water once a week. Toonies are very heavy feeders.
Yours might grow faster with more food.
If the toonie foliage gets yellowish that is a sign of mineral deficiency.
Iron manganese and something else, I forget at the moment.
I just learned this looking up growing info on them since I had so many seedlings this year. Make sure your fertilizer provides those nutrients or you might have weak yellow plants.
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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