Dahlia Tubers might not look that pretty but their blooms are spectacular! Dahlia require full sun and prefer rich well-drained soil. Perfect for sandy, loamy or acidic soils. Can be planted in containers, but will require staking. For larger varieties, (3′ ), we recommend staking when you plant as stems are rather brittle. Hardy to zones 8-11 but with heavy mulching some varieties can overwinter in the ground up to zone 6. You can dig each tuber after frost has blacken foliage and store until Spring.