The Amaryllis is a popular winter-blooming houseplant prized for its dramatic, trumpet-shaped flowers. Many gardeners move these plants outdoors during the summer months to allow the foliage to photosynthesize and replenish the bulb’s energy reserves. To ensure the plant re-blooms, the bulb must undergo a specific period of forced dormancy, requiring a timely transition indoors that mimics its natural seasonal cycle.
Identifying the Critical Timing for Transition
The timing for moving the Amaryllis indoors is determined by the outdoor temperature. Since the bulb is tender, it cannot tolerate freezing conditions; temperatures at or below 32°F (0°C) will damage the plant tissue. Therefore, the plant must be brought inside before the first expected frost.
A conservative approach is to transition the plant when night temperatures consistently drop below 50°F (10°C). This threshold usually occurs between late August and mid-September, depending on the local environment. Allowing the plant to remain outdoors in cooler temperatures for a short period signals the end of the growing season and encourages the necessary dormancy phase.
Preparing the Amaryllis for Dormancy
Inducing dormancy begins with a deliberate change in care once the plant is moved inside. Starting in late summer or early fall, cease all fertilization to stop active growth. Simultaneously, gradually withhold water, which deprives the bulb of the resources needed to sustain its foliage.
This lack of resources encourages the plant’s energy to consolidate back into the bulb for the next bloom cycle. The foliage will naturally yellow and wither, signaling the start of the rest period. Once the leaves have completely dried out and turned brown, cut them back, leaving a stalk of about one to two inches above the bulb’s neck.
Pre-Storage Inspection
If the potted bulb spent the summer submerged in a garden bed, remove it and clean any excess soil or debris from the pot. Before final storage, remove the top layer of soil and check for pests that might have taken up residence. The bulb itself should be firm and free of soft spots, which indicate rot.
Indoor Storage and the Dormancy Phase
The dormant Amaryllis bulb requires a specific environment to complete its rest period. Ideal conditions include darkness and a cool temperature range of 50°F to 60°F. Successful storage locations include a cool basement, a dark closet, or a non-heated garage that remains above freezing.
This cool temperature provides the necessary chilling period to reset the bulb’s internal clock and initiate flower bud development. The bulb must be kept completely dry during this phase. Moisture combined with cool temperatures can quickly lead to fungal growth or rot.
The dormancy period should last a minimum of eight weeks, and ideally between 8 and 12 weeks, to ensure the bulb is fully rested. While in storage, inspect the bulb periodically for mold or premature sprouting. If new green growth appears, the bulb is ready to break dormancy early and should be moved to the next phase.
Waking the Bulb and Forcing the Bloom
To force the Amaryllis to bloom for winter, break the dormant period four to eight weeks before the desired flowering date. Move the potted bulb from its cool, dark storage location to a warmer spot receiving bright, indirect light. Give the soil an initial, light watering to signal the end of the dry rest period.
A warmer ambient temperature is necessary to encourage stem and root growth, with the ideal range being 70°F to 75°F. The plant requires only minimal water until a new flower stalk or leaves emerge from the bulb. Once active growth is visible, increase watering to keep the soil moist, but not saturated. Rotate the pot daily as the flower stalk elongates to ensure it grows straight toward the light source.