Pinching, also known as “stopping” or “topping,” is a cultivation technique where the main growing tip of a young dahlia plant is purposefully removed. This action interrupts the plant’s natural tendency to grow a single, tall central stalk that produces one large, early bloom. Removing the terminal bud redirects the plant’s energy, stimulating the growth of dormant side shoots. The goal is to encourage a more branched, robust, and full structure, leading to a significantly higher number of flowers throughout the season. This transforms a potentially lanky plant into a strong, bushy specimen.
When Your Dahlia Is Ready For Pinching
The timing of the initial pinch is important for the dahlia’s health and successful branching. A plant should be actively growing and well-established before this step is taken to ensure a quick recovery. The ideal window occurs when the dahlia has reached a height of approximately 10 to 18 inches, depending on the variety’s vigor.
A more reliable indicator than height is the number of true leaf sets present on the main stem. The plant should display at least three to five pairs of leaves along the central stalk before pinching is considered. Pinching the plant too early can stunt its growth and slow down its recovery time. Waiting for the dahlia to develop this foundational foliage ensures it has enough photosynthetic capacity to support the new lateral growth.
Locating the Perfect Pinch Point
The precise location of the cut is directly above a leaf node, which is the point where the leaves emerge from the stem. To locate the pinch point, first identify the central stem’s terminal bud, the small, tender growth at the very top. This bud is responsible for the plant’s vertical growth.
Count down the main stalk to find the third or fourth pair of leaves. The selection depends on the plant’s natural habit; leggier plants may benefit from a lower cut above the third set, while sturdier ones can be pinched higher. The cut should be made just above the chosen leaf node, aiming to remove the top growing tip and the small segment of stem directly below it.
This node contains two dormant axillary buds situated in the ‘V’ where the leaf stems meet the main stalk. Removing the terminal bud eliminates the source of the growth-suppressing hormone auxin, which allows these dormant buds to activate. The cut can be done with clean, sharp scissors or shears, or simply by pinching the soft tissue off with your thumb and forefinger. Making a clean, precise cut just above the node is necessary to avoid damaging the new shoots.
Post-Pinch Plant Care and Growth
Immediately following the pinch, the dahlia requires consistent attention to support the redirection of its energy. Adequate deep watering is important to sustain the underlying root system as it prepares to fuel multiple new shoots. Dahlias require deep watering two to three times a week, especially during dry periods, to ensure moisture reaches the tuber’s roots.
Applying a balanced fertilizer after the pinch will provide the necessary nutrients to encourage vigorous lateral development. The plant temporarily shifts its focus from flower production to vegetative growth, meaning it needs fuel for building new stems and leaves. Within a week or two, the gardener should observe the activation of the dormant buds at the node just below the cut.
Two new side shoots will typically emerge from this point, replacing the single central stem that was removed. These new branches will grow outward, giving the plant a fuller, more rounded, and less top-heavy structure. This bushier form makes the plant stronger and creates multiple new growing points. Each of these new stems will eventually produce its own set of blooms, resulting in a greater flower yield later in the season.