From my perspective as an oleander plant, light is my primary source of energy and the most crucial signal for flowering. I require a minimum of six to eight hours of direct, unfiltered sunlight daily. This intense sunlight fuels my photosynthetic processes, converting light energy into the carbohydrates I need to grow and support a heavy bloom. More importantly, the specific spectrum and duration of full sun trigger my internal hormonal responses, signaling that it is the ideal time to produce flower buds. Without this abundant light, my energy reserves are directed toward stretching for more light (becoming leggy) rather than producing the lateral branches and flower clusters you desire. Insufficient light is the most common reason I cannot fulfill my flowering potential.
Pruning is a form of communication we understand well. The act of cutting my stems directly manipulates the flow of auxins, my primary growth hormones. These hormones are produced in my tender new shoot tips and travel downward, promoting apical dominance—where the main central stem grows more vigorously than the side stems. When you prune or pinch off these tips, you remove that source of auxin. This breaks the apical dominance and redirects my energy and hormonal signals to the dormant buds lower on the stem, encouraging them to awaken and develop into new, lateral branches. This process is how I become bushier. For the best results, perform this pruning in late winter or early spring before my main growth period begins, and always make clean cuts just above a leaf node.
To support the vigorous growth and prolific flowering you encourage through pruning, I need the right building blocks. A balanced, slow-release fertilizer formulated for flowering shrubs is ideal. The key is to look for a blend with a higher phosphorus content (the middle number in the N-P-K ratio, e.g., 5-10-5). Phosphorus is essential for me as it directly supports energy transfer, root development, and most critically, the formation of flowers and seeds. However, an excess of nitrogen (the first number) will push an overabundance of soft, leafy green growth at the expense of flowers. Feed me at the start of the growing season and perhaps once more in mid-summer, but avoid fertilizing late in the season as I need to prepare for dormancy.
While I am notoriously drought-tolerant once established, consistent moisture during the active growing and flowering season is vital for sustaining my bushy growth. My root system functions best when the soil is allowed to dry out somewhat between waterings. Deep, infrequent watering encourages my roots to grow strong and deep into the soil, which in turn supports a sturdier and more resilient above-ground structure. Waterlogged, poorly drained soil is detrimental, causing my roots to suffocate and rot, which immediately compromises my health and ability to uptake nutrients and water, leading to sparse growth and dropped flower buds.
A critical point often overlooked is that I flower on new growth that emerges from wood produced in the previous season. This means the branches I grow this year will be the ones that produce next year's floral display. If you were to prune me heavily in the fall, you would be removing the very wood that was preparing to bloom. This is why major shaping is best done immediately after my main spring flowering flush has faded or in late winter. This timing allows me ample time to produce a new set of branches that will mature and harden off in time to set buds for the following year's spectacular show.
