Dahlias: Single Tubers vs Tuber Clumps

Which is More Likely to Grow into a Healthy Dahlia Plant?

Spring planted dahlias can be purchased as clump divisions or single tubers, or as full tuber clumps; which is better?  After many seasons of testing, we can confirm that both will grow just fine. 

Small farm growers tend to sell individual tubers. An end-of-season harvested clump can be cut to produce multiple single tubers and this translates into more dahlias for the grower to sell. Each tuber must have an eye, as this is what sprouts and grows into a new plant. If a clump has 3 to 5 eyes, a knowledgeable trimmer can get that number of individual tubers from the clump. However, this takes time, skill and patience.

Dahlia farmers with large growing fields have the space to produce more dahlia plants, each of which can be harvested for a saleable clump. These larger commercial growers usual prefer to sell full clumps rather than invest the time and money in trimming to individual tubers. Full clumps typically have some small or shriveled tubers along with the viable ones. We like to trim out the not-going-to-grow tubers before planting. Here's how to do that: Preparing Dahlia Clumps for Planting.

Basket of washed dahlia tubers
We choose to offer full clumps because with more eyes, there can be multiple stalks. Fuller plants. A safety net if one stalk gets damaged. 

This avid home gardener's basket of washed, wildly irregular dahlia roots (right) is ready for winter storage.

Single trimmed dahlia tubersThe ready-to-plant tubers below were supplied by a small grower. Writing the name of the variety on the tuber is common practice and a helpful way to reduce the likelihood of mix-ups.

Note: the difference in tuber size and shape based on variety. This is normal and to be expected. 

Similar size variances occur with full clumps. Some dahlia varieties tend to produce huge clumps - Shiloe Noelle is one - while others mature with clumps on the small side. Sweet Nathalie is an example of a small clump dahlia. Small clumps are not a cause for concern. As long as there is an intact collar (where the sprouting eyes are located) and at least one tuber to support the plant as it begins to grow, the dahlia will grow just fine.