When planting tuberose bulbs, keep in mind that timing and location are key for success with these flowering plants, due to their lack of hardiness. Tuberose bulbs should be planted in the springtime after the last frost, as they are not cold-resistant. They require full sun but can react negatively to extremely warm temperatures. The bulbs can be stored indoors in autumn and reused the following spring.
Plant the bulbs approximately 8-10 inches (20-25 cm) apart, and make sure that each bulb has about 2 inches (5 cm) of soil over it. Choose a location with direct sun. For areas that reach summer highs of 95 degrees F (35 degrees C) or higher, plant tuberose bulbs where they will receive partial shade during the hottest part of the day. Extreme heat can shrivel tuberose flowers or prevent buds from opening.
New growth might not emerge from a tuberose bulb until up to four weeks have passed. Tuberoses typically bloom in midsummer and could continue producing flowers until temperatures drop. All tuberose bulbs should receive water on a weekly basis. They will perform best if they are planted in well-draining or sandy soil. Provide fertilizer during the warm months to encourage continued growth and blooming.
When all of the tuberose's blooms have faded, continue watering the plant weekly until the foliage has yellowed and died away. At this point, the foliage can be cut back. Cutting down tuberose foliage too early can harm the chances of the bulb producing blooms the following year.
The tuberose is not cold-tolerant, making it feasible as a perennial only in areas that are warmer than USDA Hardiness Zone 8. In colder locales, the tuberose bulbs can be removed from the ground after the first frost for use in subsequent years. Prepare the bulbs for removal by gradually reducing water about three weeks before the first frost is expected. Allow tuberose bulbs to dry in the open air for several days, then place them in a paper bag or cardbox box filled with peat moss for winter storage indoors.
Optionally, a tuberose plant can be maintained in a container for ease of use. Rather than overwintering or discarding tuberose bulbs, a gardener can simply transport the container indoors during the winter months. In spring, the tuberose should be repotted with new soil. New tuberose bulbs can be planted in containers indoors up to six weeks before the last spring frost.
Tuberoses have tubular white flowers on tall spiky stems up to 36 inches (91 cm) tall. Several blooms can appear on each stem. Known for their pungent fragrance, these flowers are popular at weddings and in cut flower arrangements. The scientific name of the tuberose is Polianthes tuberosa.