Autumn Joy sedum (Sedum spectabile) is an easy-to-grow succulent that will thrive in most any soil. Perennials.com describes the flowering process as "green broccoli-like buds in mid-summer, which gradually open into enormous dusty-pink flower heads, finally deepening to rich, bronzy red."
Plant Autumn Joy in sandy, well-drained soil in USDA hardiness zones 4 to 9. The soil can range anywhere from alkaline to acidic. Autumn Joy is not very choosy. It will grow in partial shade but does best in full sun.
Water your sedum once a week for the first month after it is planted. After it is established, water only when the soil is completely dry. Autumn Joy is fairly drought-tolerant. If overwatered, the stems will become waterlogged and rot.
Fertilize minimally or not at all. If your plants have suffered through a particularly long dry season or are planted in extremely poor soil, use a very light dose of slow-release general fertilizer.
Propagate your sedum by "window rooting." Cut the fleshy stems in the fall and lay them horizontally in a sunny window. Within the next month, each leaf node will produce a shoot that can be removed and rooted. During the summer, you can simply snip off a 2- to 3-inch tip from the plant and stick it directly in the soil. Water well, and let it root on its own.
Water the sedum the day before dividing. Cut the plant to within 6 inches of the ground.
Insert a shovel or gardening fork into the ground in a circle around the plant, 4 to 6 inches from the base.
Pry the plant from the soil with the shovel and lift it from the ground. Shake it gently to remove loose soil and cut away any dead leaves.
Use a large knife or the shovel to slice the root ball in half. If the pieces are still large, slice them each in half again.
Plant the Autumn Joy sedum divisions quickly so they don’t dry out.
Taller than most sedums, autumn joy grows 18 to 24 inches high and about as wide. The fleshy leaves are gray-green and the flower clusters start as pale pink about mid-summer. Blossoms take center stage in fall when they turn a rosy-salmon and deepen to brick red with frost. The plant is hardy in zones 3 to 8.
Like all sedums, autumn joy is a succulent and will tolerate drought. It requires full sun and well-drained soil. The soil should not be too rich, or the stems will collapse once the plant blooms. Early spring is the best time for division.
Autumn joy works well in the flower border and is attractive to butterflies and bees. It pairs well with grasses, black-eyed Susans and other autumn bloomers such as asters and chrysanthemums.
Sedums actually do better being somewhat neglected. Too much water or fertilizer can cause their stems to flop.
Autumn joy is attractive from spring until fall. If stems go uncut, it is decorative in the winter. The stiff flower heads have a sculptural quality when dusted with snow, and serve as a shelter for wildlife.