Amaryllis (Hippeastrum) is a bulbous plant known for its dramatic, trumpet-shaped flowers. While often grown as a winter houseplant, Amaryllis requires a summer period outdoors to successfully rebloom. This outdoor growth allows the bulb to rebuild energy reserves depleted by flowering, storing the necessary starches and sugars for the next floral display. Moving the plant outside during the warmer months is a fundamental step in its annual care cycle.
Optimal Outdoor Location and Planting
The transition outdoors should only happen after all danger of frost has passed, typically when nighttime temperatures consistently remain above 50°F (10°C). Moving the potted bulb outside gradually helps the plant acclimate to the brighter, unfiltered light and fluctuating temperatures. A spot receiving bright, indirect light is ideal, though morning sun with afternoon shade works well, as intense mid-day sun can scorch the foliage.
The Amaryllis can remain in its container or be planted directly into a garden bed for the summer. Regardless of location, the soil must offer excellent drainage to prevent waterlogging and bulb rot. If planting in the ground, amend the soil with sand or compost. When planting or sinking the pot, keep the top one-third of the bulb exposed above the soil line for proper growth and health.
Watering and Fertilization During Active Growth
Once the Amaryllis is settled outdoors and actively growing its strappy green foliage, its watering requirements increase significantly. The plant needs consistent moisture during this summer growth phase to fuel photosynthesis and bulb enlargement. Allow the top inch or two of the soil to dry out slightly between waterings, then water deeply until it drains from the bottom of the pot.
Fertilization is necessary during this period to ensure the bulb stores enough energy for the next bloom cycle. Apply a balanced, water-soluble fertilizer, such as a 10-10-10 or similar formula, every two to four weeks throughout the active growing season. This regular application helps strengthen the bulb and encourages the development of next season’s flower buds.
Post-Bloom Care and Foliage Management
The period immediately following the fading of the flowers is when the bulb begins its energy-storing phase, making foliage management important. Once the last bloom on a flower stalk (scape) has wilted, cut the stalk back cleanly to about one or two inches above the bulb. Cutting the spent scape prevents the plant from expending energy on seed production.
The green, strap-like leaves must be left intact, as they are the plant’s energy factories. Through photosynthesis, the leaves convert sunlight into carbohydrates, which are stored within the bulb. The bulb’s ability to rebloom the following year is directly linked to the health and longevity of this foliage. Never cut off the leaves while they are still green.
Inducing Dormancy and Winter Preparation
To prepare the plant for reblooming, a period of rest (dormancy) must be induced in late summer or early fall, usually around late August or September. This process begins by gradually reducing and then completely stopping both watering and feeding. Withholding moisture signals the end of the growing season, prompting the foliage to naturally yellow and wither.
The potted Amaryllis must be moved indoors before the first frost, as the bulb is not tolerant of freezing temperatures. Place the entire pot in a cool, dry, and dark location, such as a basement or closet. The temperature should remain consistently between 50°F and 55°F (10°C to 13°C).
This cool, dry environment is maintained for eight to twelve weeks, which is the required dormant period to reset the plant’s internal clock for flowering.
After the foliage has completely died back and turned brown, it can be trimmed off near the neck of the bulb before storage. The bulb remains in its pot, unwatered, for the duration of the rest period. Bringing the bulb back into warmth, light, and water will initiate new growth and lead to flowers approximately six to eight weeks later.