Yes, perfection does exist … in some works of art, but not in the garden. There is almost always something not quite right about any plant you grow: insect holes in a leaf, powdery mildew on lower leaves, a brown spot here and there, etc.
While many gardeners immediately reach for the most powerful pesticide they can find at the first sight of a problem, they’re usually wasting their time. Often the insect that drilled the holes is already moved on and mildew is usually the final stage of a disease that started weeks before and has already stopped spreading, so why bother? Plus often, Mother Nature has already sent in her clean-up team in the form of beneficial insects and do you really want to thwart her plans?
When the disease or insect or “problem” is minor or out-and-out inconsequential in the long run, no treatment is really necessary. At any rate, a few pierced, chewed, spotted, or swollen leaves don’t really disfigure the garden, at least not if you squint a little.
That’s why I suggest you apply the “15 pace rule.” It couldn’t be simpler! Before treating, step back 15 paces: if you can’t see the problem at 15 paces, it’s probably not worth treating! And yes, long-time readers, I’ve said this before, but it’s worth repeating!
Among the problems that are trivial and rarely worth reacting to are leaf miners, late season powdery mildew, leaf and stem galls, and yellowing lower leaves.