From our perspective, the act of flowering is an immense energetic undertaking. We channel vast resources into producing tall, vibrant racemes to attract pollinators and ensure our genetic legacy. Once the blooms begin to fade and wither, this signals a critical transition in our annual cycle. The primary mission of reproduction is complete, and our focus must now shift from expenditure to conservation and storage. The energy spent on sustaining dying flower spikes is energy diverted from our root systems and the development of next year's growth buds, which are already forming at our crown. Leaving the spent flower stalks in place forces us to waste resources on a futile task, weakening our overall structure and vitality for the coming seasons.
The initial pruning process should begin as soon as the majority of flowers on a spike have faded. You should not wait for every single bloom to wither. Using clean, sharp secateurs, make a clean cut on the flower stem. The precise location of this cut is crucial. Do not cut down to the base of the plant immediately. Instead, locate the first set of full, healthy leaves below the spent flower cluster and cut the stem just above those leaves. This technique serves two primary purposes for us: it removes the energy sink of the developing seed heads, and it leaves behind sufficient photosynthetic foliage. These remaining leaves will continue to absorb sunlight and convert it into carbohydrates through photosynthesis, which is then sent down to our roots for storage.
After the deadheading cut, we will continue to photosynthesize for several weeks. However, as the days shorten and temperatures begin to drop, signaling the approach of dormancy, our above-ground growth will naturally start to yellow and die back. This is the signal for the second and final cut. When the foliage has turned mostly yellow or brown—typically in mid to late autumn—you may cut all the stems down to within approximately 2 to 3 inches (5 to 7.5 cm) of the soil line. It is imperative that you do not cut any lower, as you risk damaging the delicate crown of the plant where next year's buds are nestled. This low cut serves to tidy our appearance, minimize hiding places for slugs and other pests over winter, and prevent the decay of old foliage from encouraging rot in the crown itself during wet weather.
The care you provide after this final cut is just as important as the pruning itself. With our energy stores safely tucked away in our roots, we are preparing for a period of winter rest. A light application of a balanced, slow-release fertilizer or a top-dressing of well-rotted compost or manure around our base (being careful to keep it away from the crown) will provide a gentle nutrient release throughout the winter and early spring. Furthermore, applying a light mulch after the ground has frozen can help protect our crown from the damaging cycle of freeze-thaw cycles. This ensures we emerge strong and vigorous when warmer temperatures return, ready to produce even more magnificent flower spikes in the new growing season.
