Most saxifrages (it's a big group) like full sun but will do well with a few hours of shade. Some turn crispy in a natural setting during hot seasons. They also die out in the center and some fringes. If your saxigrage has big brown parts...it's healthy and doing what is natural.

Just lift the edge of the plant and pull dead sections away. Don't pull straight up but sideways, where they die in the middle just put a natural looking rock in the center of the plant. Also, any parts you pull out with even a bit of green can be planted to start a new mound. They don't need much, if any, of a root. This is the time of year to turn one plant into as many as you want by just pulling away however many rosettes you want. They can rooted right in the gound or, if it's real hot, then put them in small pots out of the hottest sun until mid September and then plant them in the ground.

Hi, depends on the type. If they are mossy types (have softish feathery leaves) then they may well need some shade or they will fry. If they are one of the hard types, Kabschia or silver and they are going brown, that's not so good as they take a while to grow over. I thought the same for mossy's but I don't grow them anymore.

Yes you are seeing burnout I live in your zone too And grow many of the sax. as I write now its to late to move them but if you have not they will be ok during the winter. you do have them planted on a slope or rock wall correct! I have seen them grown in as little as 3 hours of direct sun and they do fine as long as the soil is like you say.

First of all I live in the Pacific Northwest and Saxifraga (MAROON BEAUTY)is gowing under my cedar tree in the shade. The other one Saxifraga ( Rubriflia) I keep in a old wash pan near the house & it gets a lot of rain, but is well drained. Booth of those are in a protected area from frost. I had read they that they can grow in Zone 7 & I live in Zone 8 they've done pretty good so far. The have just bought 2 new saxifragas, one is S' Mitella hallii & the other is S' Zimmerteri & because they are new I divided them up and put 1 half in with with each of the areas I had told you about before. They are in general location of my other Saxifragas. Hopefully they make it through our wet winters. Don't give up they are wonderful plants.

Yes, I have found saxiphrage arendsii needs shade. I grow it on the north side of an east facing rock bed. It does better some years than others, but has persisted in zone 4 for over 10 years. I also like the lime-encrusted saxiphrage, though it doesn't have such pretty flowers. Try mulching your plants with evergreen boughs after the ground freezes, that helps them overwinter in better shape.