Three years of trial and error to stop my hostas from scorching by August
I've got about a dozen hostas scattered around the north side of the house and for the first two summers every single one of them looked rough by late July, edges crisping up brown no matter how much I watered. Took me embarrassingly long to realize the "north side" wasn't actually shaded the way I assumed, there's a gap between two neighboring roofs that lets afternoon sun rake across that whole bed from about 2pm to 5pm in summer.
This year I finally moved the worst offenders, a couple Sum and Substance and one June, over to a spot that gets filtered light under a maple instead. Night and day difference. The Sum and Substance especially seemed to sulk for about three weeks after transplanting (drooping leaves, a couple yellowed) but bounced back hard once it settled in and now has leaves the size of dinner plates with zero scorch.
What surprised me most is how much variety-to-variety difference there is in sun tolerance even among ones marketed as "part shade." My Francee handled the rough spot fine the whole time, barely any browning, while the June types were the first to fry every single year. I'd read that blue-leaved hostas are more shade dependent than green ones but didn't really believe it until I watched it happen in my own yard for three seasons straight.
Also started mulching heavier this year, maybe two inches of shredded bark, and I think that helped keep the roots cooler even in the spots that still get some midday sun. Combined with the move, watering deeply twice a week instead of a little every day, it's the first summer none of my plants looked stressed by the end of it.
Curious if anyone else has had a specific variety that just refuses to tolerate the amount of sun the tag claims it should handle. Feels like the tags are more of a starting guideline than an actual rule.