Delphiniums are prized garden perennials, known for their towering spires of intensely colored flowers that can reach heights of six feet or more. However, the sheer weight of these dense flower spikes, combined with their naturally hollow and somewhat brittle stems, makes them highly susceptible to wind damage and bending, often causing them to collapse. To ensure these magnificent blooms remain upright and undamaged throughout the growing season, staking is a necessary and proactive intervention every gardener should employ.
Determining the Right Time and Need
Delphinium stems are characteristically fistular, meaning they are hollow, which compromises their structural rigidity against lateral forces like strong breezes. The large, water-filled flower racemes also create a heavy load that the thin stem cannot reliably support once fully developed. Staking must occur long before the plant shows any signs of distress or lodging.
The optimal time to install support is when the plant’s vegetative growth is approximately 12 to 18 inches high, well before the flowering stalk begins its rapid ascent. Implementing support at this early stage minimizes root disturbance and prevents damage to developing tissues. Waiting until the flower spikes are heavy and leaning makes the process far more difficult and risks irreversible damage to the plant structure.
Essential Tools and Support Options
Selecting the appropriate support materials is the first step toward successful staking. Common choices include slender bamboo canes or rigid metal stakes, such as thin rebar, which offer significant resistance to bending and are reusable for many seasons. The stake length should be chosen to reach just below the anticipated mature height of the flower spike, ensuring the rigid support remains discreetly hidden once the plant is in full bloom.
For securing the stem, soft materials like natural jute garden twine or flexible, wide plastic plant ties are preferred, as they prevent abrasion against the delicate epidermal layer of the stem. Gardeners generally choose between single-stake support for individual, dominant stems or the corralling method. The corralling technique uses three or four stakes placed around a clump, connected by twine to create a supportive enclosure for multiple plants.
Step-by-Step Guide to Securing Delphiniums
Begin the physical staking process by positioning the chosen stake carefully into the soil. Insert the stake six to eight inches away from the plant’s crown to avoid damaging the shallow, radiating root system. Drive the stake deeply into the ground, often at least a foot, to ensure it can withstand the leverage exerted by a tall, wind-blown plant later in the season. Positioning the stake on the side of the plant that faces the prevailing wind offers the best mechanical advantage against strong gusts.
Once the support is stable, the plant stem can be carefully attached using the figure-eight tying technique. This involves looping the twine around the stake, twisting it in the middle to form the figure-eight shape, and then looping the other end around the stem. This small twist creates a buffer that prevents the stem from rubbing directly against the rigid stake. The initial tie should be placed low on the stem, securing the plant while it is still relatively short.
As the delphinium grows, additional ties must be added every 12 to 18 inches up the stalk. Secure the stem just beneath a developing flower node for maximum leverage. This gradual, incremental support ensures that the stem is consistently secured at multiple points along its length. By distributing the load across several anchor points, the risk of a sudden snap or break under high wind stress is significantly reduced.
Post-Staking Care and Seasonal Adjustments
Ongoing vigilance is necessary after the initial support system is established. As the delphinium stem naturally thickens throughout the season, it is important to regularly check the existing ties to ensure they are not constricting the expanding tissue. A tie that is too tight can girdle the stem, interrupting the vascular flow of water and nutrients.
New ties must be added promptly as the flower spike elongates, always placing them just below a developing flower bud or node for maximum stability. After the main flower spire fades and is cut back, the plant often produces smaller, secondary side shoots from lower nodes. These subsequent blooms, though shorter, may also require individual ties or adjustment to the corral system to maintain an attractive, upright display.