Mine have had problems with sun scorched foliage for the last two years because the dogwood tree that I planted them under is not as full and dense as it was due to the drought and is not providing as much shade as it has in non-drought years.
Although I have excellent drainage, I did add quite a bit of decomposed granite to my back fill which only consists of native soil because I wanted to mound the plants up a bit and didn't want to use compost in the back fill.
Looks like I am not going to have to worry about sun scorch for a while because the smoke from the fires on the other side of the mountain has reduced the impact of the sun on all of my plants. I doubt if they will get the fires out for several weeks.
@springcolor, Julia ... when you write about amending your heuchera bed are you planning to do that this fall or wait until next spring ? I can't purchase heucheras up here, but have noticed that several online nurseries have them on sale. I was wondering if it would be wise to purchase the sale plants and plant them next month. Also, it's time to divide my 'Amethyst Myst'. From what I've read planting and dividing should be done in spring, but this is such an odd year weather wise could I do this in fall ?