Dahlia plants are perennials that have a limited range of hardiness, from zones 8 – 10.
For this reason where gardens are located in the north, each fall Dahlia tubers require being dug and stored if they are to be saved for growing next season
Digging Dahlia Tubers
Dahlia tubers should be dug up prior to the first hard freeze or killing frost, whichever comes first. The dahlia plant should be cut down leaving a short stem.
Mulch around the plant should be cleared away, then taking a fork or shade type shovel, approximately one foot away from the stem, cut around and gently pull back on the tool’s handle. This technique should be used around the entire plant.
After lifting the tubers out of the ground, remove loose soil. With a watering hose, lightly wash away any plant debris remaining.
Small roots and the stalk should be cut away. Eyes on a tuber indicate the beginning of a new plant; only tubers with at least one eye are viable and should be kept. Older tubers, called the mother plant, from previous years growth, do not grow as well the next year; these should be discarded.
Preparing Tubers for Storage
Dahlia tubers must be dried before storing. After washing, gently pat dry and leave to air dry a short time. Depending on humidity levels, it can take minutes or hours.
Gardeners store tubers in many types of material. The material is meant to protect the tubers from rot or shriveling. Suggested materials include vermiculite, sphagnum peat moss or sawdust.
Tubers are protected from light by storing them in containers. The storage room should be frost free with temperatures around 45 º F such as an unheated garage or attic. Tubers should be checked monthly, plan to store dahlias where they are easily accessible.
For gardeners who have many dahlia tubers labeling or bagging will help identify each type during spring planting. Use an indelible pencil for marking or bags cut with many tiny holes.
Dahlia flowers are beautiful summer plants for any garden. Northern gardeners find storing the dahlia tubers an economical way to multiply plants for next year’s growing season.