Sedum takesimense 'Atlantis' is a variegated stonecrop with fleshy, blue-green leaves edged in creamy yellow, forming a low spreading mat. In summer it produces flat-topped clusters of bright yellow, star-shaped flowers that attract bees and smaller butterflies. The variegated foliage holds visual interest from spring through fall and is semi-evergreen in warmer zones.
Native to Ulleung Island off the coast of South Korea, S. takesimense tolerates poor, dry soils and suits rock gardens, slopes, wall crevices, and the front of mixed borders. It spreads at a moderate pace and can suppress weeds on well-drained, sunny sites. Standing moisture, particularly in winter, is the primary cause of plant loss. A gritty or sandy soil, raised positioning, and good air circulation are more important than fertility or irrigation. Avoid heavy clay or low spots.
Stem cuttings root readily in summer with minimal effort. Division in early spring refreshes congested clumps and is the standard method for increasing stock, since 'Atlantis' does not reliably reproduce its variegation from seed.
Crown Rot
Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.
Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.
Fungal leaf spot
Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.
Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.