Perennials: Rock gardening in non-alpine climates, 1 by Pistil

Pistil wrote:
Well I went out this afternoon to do a bit of yardwork, and mostly to take some photos (including my Seattle rock/clay garden plants). I hadn\'t been out more than 3 minutes when my young neighbor showed up. He loves to do yardwork with me so my plan immediately turned into \"cut back everything\" since he likes to use clippers. We worked for 2 hours, then it was too gloomy for photos. I have upped his rate this year to $1 per hour.

Anyway, about the non-alpine rock garden.
I have had poor success with dianthus, not sure but I think it may be the clay. Ditto Pulsatilla which I think I have tried 3 times, does not overwinter. Arabis lives, in a sad and diminished manner. The short Phlox subulata is a total loser. ditto Arenaria, Aubrieta. Verbena \'Homestead purple\'. Tulips. Mazus reptans. Saponaria. Silene. Blue-eyed grass. Small campanulas seem either to die or become invasive. Man this is a big list of failures.

Come to think of it, perhaps it is my acid soil, I think in the Alps it is often limestone as well as \"sharp drainage\' in gravel. I bought a bag of limestone chips last year, and sprinkled them around some lime-lovers. Maybe I will try Pulsatilla again. They do grow wild in the mountains here.
I have considered getting a load of gravel, and making a layer 8\" deep on top of my clay, like a scree pile but that seems to be a lot of work.

Hmm, let me focus on plants that DO work here in my non-alpine garden. I have plenty.
Aurinia saxatilis (Gold dust Alyssum)
Iberis sempervirens (Candytuft)
Bergenia cordifolia
Cotula \'Tiffindell Gold\' is totally cute, creeps along on the surface. Now self seeding in the gravel of my walkway between pavers.
Lithodora diffusa I like \'White Star\' better than \'Grace Ward\' but it will climb. High.
Crocus
Iris cristata \'Abbey\'s Violet\' survives in dry shade on slope near my rock wall. This year I will spread it around and try sun too.
Yellow-eyed grass
Heathers but most get way too tall
Eucomis I am playing around with various spp embedded in the rock walls
Erysimums (wallflowers) various, not all, are perennial.
Lavender, as long as on a slope, does just fine here in solid clay!
I have a dwarf hyssop I LOVE, about 10\". Saved seeds this year. In clay, part sun.
I have encrusted saxifrage now in two spots, on edge rock wall and steep spot.
Antirrhinum hispanicum (Spanish snapdragons) are hardy, on rock wall edge bloom 8 months a year. Birder you might try these in your rocks, Spain would be hot (maybe not humid tho).
Rhododendron impeditum an \"alpine\" Rhody from China, is a tough survivor in Seattle, very popular for good reason.
Don\'t forget Lamb\'s Ears. Melt in winter and are hideous, now already reviving.
Sedum \'Elsie\'s Gold\' is in dry shade under a tree. Does not flop!! Sedums are supposed to need sun? I must divide and try it in a sunnier spot.

What is most interesting about this list is how many plants I would not have thought would survive here are doing just fine. Most of them do best if near the edge of a rock wall, or on a steepish slope, so the clay does not remain soggy. Others that seemed a sure thing won\'t behave as perennials. Some things are supposedly for sun but do fine here in shade.
As I said, I am also playing around with my \"Lime Chips\" to alter the pH in the immediate vicinity of a plant.Too soon to tell.
I also now have a bag of \"Chicken Grit\" which is granite gravel, I thought I might make little pockets of this just behind the rocks on some walls, to try some things like Pulsatilla again.