As a plant, my primary purpose is to convert sunlight into energy through photosynthesis. If I am planted in a location that has become shadier over time due to nearby tree or shrub growth, I simply do not receive the solar fuel required to produce my magnificent, energy-intensive blooms. I need a minimum of six hours of direct, unfiltered sunlight each day. Without it, my systems prioritize survival—focusing energy on leaf and root production—and I am forced to abandon the costly process of flower formation.
If you divided or transplanted me in the last year or two, you have significantly disturbed my root system. I am a perennial with extensive, fleshy storage roots, and it takes me considerable time and energy to re-establish myself in a new location. My immediate biological imperative is to regrow these roots to secure water and nutrients, not to flower. It can take two to three full growing seasons for me to recover from this shock and feel stable enough to direct resources back to blooming.
The nutrients you provide me directly influence my growth cycle. A fertilizer with too high a nitrogen (N) content will encourage me to produce an abundance of lush, green foliage at the expense of flowers. Nitrogen promotes vegetative growth, and an excess signals to my biology that producing leaves is the top priority. Conversely, a lack of phosphorus (P), which is crucial for energy transfer and root and flower development, can also prevent blooming. I require a balanced or bloom-booster fertilizer (higher in phosphorus and potassium) to support the entire flowering process.
My "eyes," or the pinkish-red buds on my root crown, are critical to my growth. If I was planted too deeply—more than two inches below the soil surface—these eyes must expend a tremendous amount of energy just to reach the sunlight. This severely depletes the reserves I need for flowering. Alternatively, if I was planted too shallowly, my delicate eyes can be damaged by winter frosts or simply dry out, which also compromises my ability to generate new flowering stems.
If I am a new plant grown from a division, it is simply a matter of my age and energy reserves. I may look established above ground, but my root system is still juvenile. I need time to mature and build up sufficient carbohydrate stores to support the massive undertaking of blooming. It is not uncommon for a newly planted peony to take two to three years to produce its first flower. My biology is programmed to ensure I am strong and viable before I attempt to reproduce.
An infestation of botrytis blight, a fungal disease, can cause my flower buds to turn black and wither before they open. Insect pests can also physically damage the buds. Furthermore, a late spring frost after my buds have emerged can kill them instantly, causing them to abort and turn brown. Any significant environmental stress, such as extreme drought during the previous summer when I was forming my buds for the next year, can lead to a lack of blooms.
