I've the exact problem. Can Confirm, as secretmail021 has identified, it is a very very very small insect. White-green color, approximately as wide as 1-2 human hairs, about 1.5 mm in length... you won't see them on the leaf, Instead, pick a leaf and shake/tap it over a well-lit preferably dark surface.... if they fall off, you can see them crawl. Happened with indoor potted plant that was otherwise healthy for the last month. No idea for the solution, but act fast, because it spread from a few just a few leaves to a few plants over the course of half a week. RIP basil.

That doesn't look abnormal to me. Some of mine will have little dark spots like that and end up opening up fine. The sepals are there to protect the bud, they need not be perfect. Usually the white/pink/red ones show this, the coral ones seem to have smooth and more perfect sepals. Later in the season (summer/fall) as the plants start to get ready to go dormant, my leaves may get a bit spotty and crispy but next year, they are back just fine. To see really sickly-looking peonies, see this! http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/visual-guides/peony-problems.aspx

Lots of rainy days here, David Austin's Charlotte got the black spot despite my spraying. After quite a bit of leaf drop, new growth is coming on, should I begin spraying as soon as it leafs out? or will it hurt the new leaves? I use Neem Oil, bought an organic one this time, perhaps it's not doing the job.

Thank you, Silica. I will contact the local Extension service. Meanwhile I found this on Citrus Black Spot: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/citrus/citrus-black-spot/citrus-black-spot . The description of the spots does not quite match what I am seeing and fortunately the fruit has not been affected. My lemon tree started as a volunteer. Its parents may have been commercial citrus cultivars but it grew from a seed spread by the wind or wildlife. I wasn't sure what it was when it first appeared in my garden but it was too close to a rosebush so I put it in a small pot. That was about 10 years ago. I have 2 other store-bought lemon trees but they are more than 40 feet away and so far neither has spotted leaves.