Just a follow up -- Cucumber leaves continue to get universally lighter, added more photos in hope of further diagnosis and corrective action. See ones in pots behind these, they are in separate containers (all off the ground on skids), same size. Notice they are still dark green. The cucumbers look ok, there are too many growing!

I had a coneflower with buds looking similar to yours. I finally took a bud, sliced it in half and looked at it under a microscope. I definitely found mites. I could not see the mites just by eye or with a magnifying glass. Of course, this does not rule out aster yellows, but it did make me feel a bit better. I decided to keep that plant. If you do not happen to have a microscope handy, you might be able to take the sample bud to a local group or agency that does have one. If you live near your county extension office (run through your state's land grant university), they might have a plant diagnostic lab. A local university or community college might have a plant sciences/ag department that could look at it. Sometimes even state parks with education centers have microscopes available for community use. A local Master Gardener group might be able to look at it as well. gl whatever you decide to do!

I feed mine all the time, however the food is very diluted, even more so than they may suggest on the package. I have noticed that my streps prefer natural sunlight but I still have many of mine under growlights. I also have some of the violet barn hybrids. The majority of my streps have bright green leaves. Could it be that the strep was unhealthy so the leaves weren't exactly the right color and now they are coming back correctly and you think it could be wrong? What is the hybrid's name? Buying store made mixes is tough. I would not recommend ANY if you wick water. If you wick water I would recommend buying soil from a violet greenhouse (like lyndon lyon or violet barn) You can find commercially available african violet soil (if you do not wick water), which would be ok but it is a bit heavier than most people like. The best soil mix (and easy to make!) is 1 part vermiculite, 1 part peat moss and 1 part (or a little less)of perlite. Get the coursest vermiculite you can buy. -renee

Like the two earlier post, that's natural for this plant at this time of year. Especially for one grown in full sun. I have noticed that my vine maple growing under the canopy of large conifers, the leaves are all still green, while out in the open they are showing some red.