Amaryllis (Hippeastrum spp.) is a bulbous plant with distinct growth phases that dictate its nutritional needs. To fertilize optimally, it's essential to align feeding with these cycles. The plant undergoes active growth, flowering, dormancy, and re-emergence. Fertilization should primarily occur during the active growth phase, when the plant is producing leaves and storing energy in the bulb for future blooms.
From spring to early fall, amaryllis enters its vegetative stage, producing long, strap-like leaves. This is the prime time to fertilize, as the plant requires nutrients to build reserves in the bulb. Use a balanced, water-soluble fertilizer (e.g., 10-10-10 or 20-20-20) every 2-4 weeks. Dilute the fertilizer to half strength to avoid salt buildup, which can damage roots. Focus on nitrogen (N) for leaf development and phosphorus (P) and potassium (K) for overall health and future flowering.
As daylight decreases in late fall, amaryllis prepares for dormancy. Gradually reduce fertilization to once a month, then stop entirely as leaves yellow and wither. Over-fertilizing during this phase can disrupt the dormancy process, leading to weak blooms or forced growth at the wrong time. Allow the plant to naturally withdraw energy into the bulb.
During winter dormancy, amaryllis requires no fertilizer. The bulb is inactive, and adding nutrients can cause rot or stimulate premature growth. Keep the bulb in a cool, dark place (50-55°F or 10-13°C) with minimal watering. Fertilization resumes only when new growth emerges, typically after the dormancy period ends.
After the amaryllis blooms, it shifts energy back to leaf production. Once flowers fade, cut the stalk but leave the foliage. Resume fertilizing with a balanced formula to support leaf growth and bulb replenishment. This post-bloom phase is critical for rebuilding the bulb's energy stores for the next flowering cycle.
Potted amaryllis may require more frequent but diluted fertilization due to limited soil volume. Ground-grown plants can access more nutrients naturally but still benefit from supplemental feeding during active growth. Adjust schedules based on soil quality and environmental conditions.
Yellowing leaf tips or stunted growth may indicate over-fertilization (nutrient burn). Pale leaves or weak blooms suggest under-fertilization. Flush the soil with water if salts accumulate, and adjust the feeding regimen accordingly.
