Dahlia tubers are specialized root structures that store energy for the plant to regrow each season. Unlike true bulbs, the growing points, or “eyes,” are located near the base of the old stem. The timing of your purchase is a critical factor for successful dahlia cultivation, impacting both the selection of varieties available and the quality of the planting stock. Deciding when to buy depends on whether you prioritize securing specific varieties early or inspecting the physical health of the tuber closer to planting time.
The Early Bird Advantage: Buying Online and From Catalogs
Securing the widest selection of dahlia varieties requires planning ahead, often during the winter months. Specialized growers and mail-order nurseries begin sales as early as January or February, utilizing online stores and seasonal catalogs. This early purchasing window is necessary for anyone seeking rare or highly sought-after cultivars, which often sell out quickly after the catalog release. Buying early guarantees access to the specific varieties you desire before stock is depleted.
The tubers purchased early are generally pre-orders and are shipped later in the spring, once the danger of freezing during transit has passed. Growers coordinate shipping to align with the estimated safe planting window for your climate zone. Although purchased early, the tubers arrive dormant and require proper storage until the soil is warm enough for planting. This process shifts the responsibility of months-long storage onto the gardener.
Purchasing Locally: Timing and Tuber Inspection
Buying dahlia tubers from local garden centers, nurseries, or big-box stores typically happens later in the season, usually mid-to-late spring. This timing is much closer to the ideal planting window, which is after the last frost date when soil temperatures have warmed to at least 60°F. The primary benefit of a local purchase is the ability to physically inspect the planting material before buying it.
When inspecting a tuber, look for material that is firm and plump, indicating good hydration and stored starch reserves. Avoid any tubers that appear shriveled, mushy, or show signs of mold or rot, as these are unlikely to sprout. You must confirm the presence of a viable “eye,” a small bud located on the tuber’s neck where it attaches to the old stem. A tuber without a visible eye, even if otherwise healthy, will not produce a plant.
Handling and Storage Before Planting
Tubers often arrive weeks or months before the weather is suitable for planting, making proper temporary storage necessary. The goal of storage is to keep the tuber dormant while preventing both desiccation (drying out) and rotting (excess moisture). Ideal storage conditions involve a cool, dark, and frost-free environment, with a consistent temperature range between 40°F and 50°F.
The storage medium regulates humidity and prevents moisture loss from the tuber skin. Tubers are often packed in slightly damp materials such as vermiculite, peat moss, or wood shavings, ensuring the medium is moist but never wet. Storing the tubers in plastic bags or containers that allow for some airflow helps maintain humidity without trapping excessive condensation. Regularly checking the stored tubers confirms they are not shriveling from dryness or developing mold.