The Amaryllis is a dramatic bulb plant prized for its spectacular, trumpet-shaped flowers, often forced to bloom indoors during the winter months. For the plant to rebloom in subsequent seasons, the bulb must replenish the significant energy reserves it spent producing the initial large flowers. This requires a period of active growth following the bloom cycle, and proper fertilization timing is the single most important factor in ensuring the bulb stores enough energy for future flower production. The entire feeding schedule is dictated by the plant’s natural cycle of bloom, growth, and rest.
The Critical Start: Fertilizing Post-Bloom
Fertilization must begin immediately after the plant has finished flowering, which signals the transition from the reproductive phase to the vegetative phase. Once the last flower has faded, the flower stalk should be cut down to about an inch above the bulb, but the leaves must be kept intact. The remaining foliage becomes the plant’s energy factory, using photosynthesis to convert sunlight into sugars that are then stored in the bulb for the next bloom cycle.
Begin feeding with a water-soluble fertilizer immediately after bloom, often at a half-strength dilution of the recommended amount to prevent root burn. A balanced fertilizer, such as a 10-10-10 or 20-20-20 NPK ratio, is suitable, though some gardeners favor a formula slightly higher in nitrogen during this initial growth phase to promote lush, green foliage. Nitrogen supports the growth of the strap-like leaves, while phosphorus and potassium help strengthen the bulb and roots.
The first application of fertilizer should be done only after watering the plant, ensuring the soil is moist but not saturated. Applying fertilizer to dry soil can concentrate the salts and damage the delicate root system, which is actively working to absorb nutrients. Maintaining this feeding regimen is crucial for maximizing the size and health of the bulb throughout the spring and early summer.
Maintaining Growth: Frequency During the Active Season
Once the Amaryllis is actively producing leaves and is in its full growing phase, a consistent feeding schedule is necessary for maximum energy storage. During the active growing months, typically from late spring through mid-to-late summer, the plant should be fertilized regularly. The most common recommendation is to feed the plant every two to four weeks using a diluted liquid fertilizer.
Consistency is paramount during this period because the leaves are continuously manufacturing food for the bulb, and this process requires a steady supply of nutrients. Some experts suggest a “weekly, weakly” approach, meaning a very dilute solution applied more frequently, which ensures a constant, low-level nutrient availability. The goal of this sustained feeding is to encourage the leaves to grow as large and healthy as possible, thereby maximizing the amount of energy the bulb can store for the following season’s flowers.
If the plant is moved outdoors for the summer, as is often recommended, the feeding and watering schedule may need slight adjustments due to warmer temperatures and increased light exposure, but the bi-weekly or monthly consistency should be maintained.
Preparing for Rest: Stopping Fertilization for Dormancy
The final timing decision for fertilization is just as important as the first, as it prepares the Amaryllis for its required dormancy period. Fertilizing must cease around late August or early September, depending on the local climate and when the plant is typically moved indoors. Stopping the nutrient supply is the first step in signaling to the plant that its active growth cycle is ending and that it must enter a period of rest.
By withholding fertilizer and gradually reducing the frequency of watering, the plant is naturally forced to slow its metabolic processes. This reduction in resources causes the leaves to yellow and eventually die back, which is the visual cue that dormancy has begun. The dormancy period is necessary for the bulb to re-set its internal clock and successfully initiate the flower buds for the next blooming cycle.
Continuing to fertilize past this point will encourage the plant to produce new, tender foliage, which can prevent the bulb from properly entering its rest phase. The bulb should be kept in a cool, dark place for at least eight to ten weeks without any water or fertilizer to ensure a complete and successful rest before re-initiating growth.