Greetings, human gardener. I am a Black-eyed Susan (Rudbeckia), a being of sun and soil. I yearn to show you my brilliant golden petals and dark, nurturing center. When I do not flower, it is because my fundamental needs are not being met. My existence is a balance of light, time, and sustenance. Let me explain the reasons from my perspective.
If I am a perennial variety grown from seed or a young division, my primary mission in my first growing season is not to flower, but to survive and establish a strong root system. Flowering is an immense energetic expenditure. I must channel all my energy into building a robust foundation of roots and foliage to ensure I can return for many seasons. This is a long-term strategy. Please be patient; if my leaves are green and healthy, I am simply investing in my future, and I will reward your patience with blooms in my second year.
Sunlight is my lifeblood. It is the currency I use to create the energy required to produce flowers. The term "full sun" is not a suggestion for me; it is a requirement. I need a minimum of six to eight hours of direct, unfiltered sunlight each day. If I am planted near a building, under a tree canopy, or in the shadow of larger plants, I simply cannot photosynthesize enough energy. My stems may become leggy as I stretch desperately towards the light, and my foliage might be sparse. Without adequate solar power, I cannot initiate the complex process of forming flower buds.
While I am adaptable, I have preferences. I thrive in well-draining soil. If my roots are constantly sitting in waterlogged, heavy clay, they will begin to rot, and a stressed, sick plant cannot flower. Conversely, soil that is too rich in nitrogen is problematic. Nitrogen encourages the rapid production of leaves and stems at the expense of flowers. You may see me grow tall and lush with dark green foliage, but with no blooms in sight. I prefer a balanced soil or one that is slightly leaner to encourage my reproductive phase—flowering.
This relates directly to the soil. If you fertilize me with a high-nitrogen fertilizer (often labeled for lawns), you are instructing me to focus on vegetative growth, not floral display. To encourage blooming, I require a fertilizer higher in phosphorus (the middle number in the N-P-K ratio). However, too much fertilizer of any kind can cause problems. Alternatively, if I am planted in extremely poor, depleted soil with no organic matter, I may lack the basic nutrients needed to support any growth, let alone flowers. A light application of a balanced, slow-release fertilizer or a top-dressing of compost in early spring is usually sufficient.
This is a simple matter of energy direction. If my old, spent flowers are left on the stem, I will divert energy into producing seeds within those dead flower heads. This is my natural reproductive instinct. By deadheading me—clipping off the faded flowers—you interrupt this cycle. This signals to me that I have not successfully reproduced yet, and I will often respond by producing a new flush of blooms in an attempt to set seed before the season ends. For continuous flowering, please remove my spent blossoms.
