PLANTING AND CARE
Planting times vary according to climate and season of dormancy. In warm areas it’s almost always late fall. Where winters are rugged, it can be during brief semidormancy in early September, but it’s safest in early spring when severe frosts are no longer likely and favorable weather blesses plants at the height of their annual growing power. In temperate sections spring-flowering varieties can be planted from mid-August through October, others in spring.
Lemon thyme and ivy showing results of being trimmed and kept neat
Mr. and Mrs. Alex O’Hare
Strong, healthy, pot-grown plants can be planted throughout the season in almost all areas. They transplant easily, with little disturbance and shock. In fact, whenever we acquire plants during the fall, we keep them in their pots or pot them up, and protect them in the cold frame during the winter. One of my favorite and most knowledgeable rock gardeners tells me that he always pots tender or difficult plants, and keeps them potted until their roots are fully developed, before he sets them out in the garden, no matter what the season.
Soil
Providing the proper soil is vitally important to rock-garden plants, and particularly to alpines. They’re naturally dwarfed by the rough conditions in their native mountain areas. But when they move down to our comparatively lush climates and longer growing seasons, they respond to a too-rich diet by growing too tall and rangy, with too few flowers, and they lose their charm. They do need some nourishment, of course. And they are extremely sensitive to soil textures and drainage conditions. Heavy, soggy soil causes them to rot quickly. Soil that lacks organic matter dries out too fast.
Because of climatic and other variations, I hesitate to set down any “ideal soil mix” for these plants. Instead, I suggest a basic formula that can and should be varied according to the aridity or rainfall in your area, the size and location of your rock or wall garden, the composition of your garden soil, the availability of some ingredients, and the personal preferences of the plant varieties you want to grow. Here it is:
Three parts fairly friable, fertile loam.