The Amaryllis plant, botanically known as Hippeastrum, is a popular choice for indoor gardening, appreciated for its large, trumpet-shaped flowers. This vibrant bulb, native to the tropical and subtropical regions of Central and South America, offers a burst of color when planted indoors during late autumn and winter months. The ability to manipulate its biological clock makes it a favored holiday gift.
Understanding the Amaryllis Blooming Window
The bloom period of the Amaryllis depends on whether it is growing naturally or has been commercially prepared. In its native habitat, the plant follows a natural seasonal cycle, typically blooming during the late spring and early summer (March through May in the Northern Hemisphere). This is when the bulb has stored sufficient energy to flower.
The Amaryllis bulbs sold for indoor growing have been professionally “forced” through a period of induced dormancy. This process resets the plant’s internal clock, allowing it to bloom out of season during the cooler winter months. For a newly purchased, dormant bulb, it will flower approximately six to eight weeks after planting, allowing enthusiasts to time the bloom for specific events, such as the December holidays.
How to Time the Initial Bloom (Forcing)
Timing the initial flower involves setting the planting date back by about two months from the desired bloom date. To begin, select a pot that is only slightly wider than the bulb itself, ensuring it has drainage holes. The bulb should be planted in well-draining potting mix so that roughly one-third of the bulb remains exposed above the soil line.
After planting, give the bulb a single, thorough watering to settle the soil and encourage root development. Place the potted bulb in a warm location, ideally maintaining a consistent temperature between 68 and 75°F. This warmth is necessary to stimulate the dormant bulb and initiate the growth of the flower stalk and foliage.
During this initial forcing phase, avoid watering again until you see the first signs of green growth. Overwatering before the roots and shoot are actively growing can lead to bulb rot.
Once the flower stalk and leaves begin to emerge, move the pot to a bright window and begin watering more regularly to keep the soil consistently moist, but not saturated. The flower stalk will emerge first, followed by the strap-like leaves.
The entire process generally takes six to eight weeks from planting to the full opening of the flowers. Rotate the pot every few days to prevent the developing flower stalk from leaning excessively toward the light source. Once the buds show color, moving the plant to a slightly cooler location, around 60°F, can help extend the bloom period.
The Process for Getting Subsequent Blooms
After the initial bloom has faded, the process shifts from forcing the bulb to nurturing it for the following year’s flower. Once the flowers are spent, cut the flower stalk back to about an inch above the bulb, but refrain from removing the foliage. The leaves are essential, as they perform photosynthesis to create and store the energy needed for the next bloom cycle.
Treat the Amaryllis like a standard houseplant throughout the late winter and spring, placing it in a sunny window and maintaining a consistent watering schedule. During this active growth phase, apply a balanced liquid houseplant fertilizer once or twice a month to help replenish the bulb’s nutrient reserves.
Once the danger of frost has passed in late spring, the potted plant benefits from being moved outdoors to a sunny or partially shaded location for the summer.
To re-induce dormancy, stop all watering and fertilizing in late summer, usually around August. This lack of moisture signals to the bulb that it is time to rest, causing the foliage to gradually yellow and die back. Once the leaves are withered, they can be removed.
The bulb should be moved to a cool, dark, and dry location for a minimum of eight to ten weeks. The optimal temperature during this rest period is approximately 50 to 55°F. After the required rest, the bulb can be brought out, repotted with fresh soil if necessary, and given a thorough watering to signal the start of a new growth cycle. Placing it back in a warm, bright spot will restart the six to eight week countdown to its subsequent winter bloom.