From my perspective as an Osteospermum, reblooming isn't a trick; it's a response to having my fundamental needs met. I am a sun-worshipper, a child of the South African plains. To initiate the massive energy expenditure required to produce my vibrant, daisy-like flowers, I need abundant, direct sunlight. Think of it as my primary fuel source. A minimum of six to eight hours of full sun is non-negotiable for a strong rebloom. Without it, my photosynthetic processes slow, and I simply won't have the strength to create new flower buds. I will prioritize my energy for mere survival, resulting in lush foliage but no spectacular floral display.
Water and food are crucial, but the balance is everything. My roots despise being constantly soggy; waterlogged soil leads to root rot, which is a death sentence and certainly prevents blooming. I prefer deep, infrequent watering that allows the top inch of my soil to dry out between drinks. This encourages my roots to grow strong and deep in search of moisture. As for food, I am not a heavy feeder, but a steady supply of nutrients supports continuous flowering. A balanced, water-soluble fertilizer applied every two to four weeks during my growing season is ideal. However, too much nitrogen will push my energy into producing leaves at the expense of flowers. A fertilizer with a higher phosphorus content (the middle number in the N-P-K ratio) can gently encourage my blooming mechanisms.
This is the most direct way you can communicate with me. When one of my flowers begins to fade and wilt, it signals to my system that it's time to start producing seeds. This is a genetically programmed, energy-intensive process. By carefully pinching or snipping off the spent flower head (a practice you call deadheading), you interrupt that signal. You are essentially telling me, "The attempt to set seed failed; try again." Fooled by this, I redirect the energy that would have gone into seed production into creating new flower buds further down the stem. Regular deadheading is like a constant encouragement for me to keep blooming profusely to ensure my genetic legacy continues.
Sometimes, especially in mid-summer, I might naturally slow my blooming or become a bit leggy. This is often a period of rest. A more significant pruning at this time can invigorate me and trigger a fresh wave of growth and flowering. By cutting back my stems by about one-third, you are removing old, tired growth and stimulating the development of new, budding branches from the leaf nodes lower down on my stems. This process rejuvenates my entire form, prevents me from becoming woody, and sets the stage for a magnificent flush of new blooms in late summer and into fall, as the temperatures become more to my liking again.
My blooming is intrinsically linked to temperature. I thrive and flower most abundantly in the cool to moderate temperatures of spring and fall. The intense heat of peak summer can cause me to enter a semi-dormant state where I conserve energy and pause blooming—a phenomenon often called "photoperiodism." I am not dying; I am waiting. As the nights grow longer and the air cools in late summer, I interpret this as my ideal flowering season returning. Ensuring I am healthy and well-cared-for heading into this period will allow me to respond with a spectacular second act of blooming that can last until the first frost.
