Polianthes—commonly called Tuberose—is grown for its powerfully sweet fragrant flowers. The flowers appear on erect and spikelike racemes. Individual flowers are tubular to narrowly funnel-shaped and bloom orange-red or white.
There are 13 species in the Polianthes genus. The species Polianthes tuberosa is most commonly grown and known as tuberose. It grows from a tuber-rhizome. Flower spikes appear above a fountain of narrow grass leaves.
Polianthes are members of the agave family and are closely related to century plants (Agave) and yuccas (Yucca). Polianthes are native to Mexico.
Get to Know Polianthes–Tuberose
- Plant type: Perennial from tuber-rhizome
- Growing zones and range: Zones 9-11
- Hardiness: Warm-season rhizome; grow indoors in winter
- Height and width: 18 to 42 inches (45-106cm) tall
- Flowers: Loose whorls of tubular glistening white flowers
- Bloom time: Summer to early fall
- Uses: flower borders, cut flower garden; long-lasting cut flower
- Common name: Tuberose
- Botanical name: Polianthes
- Family name: Agavaceae
Where to Plant Polianthes–Tuberose
- Grow Polianthes in full sun.
- Plant Polianthes in moist, humus-rich soil that is well-drained.
When to Plant Polianthes–Tuberose
- Plant tubers outdoors in spring in Zones 6 and warmer; in Zones 3-5 start tubers indoors 5 to 6 weeks before the last frost so that they have enough to bloom once set in the garden.
- When started indoors set containers on a heat mat to speed growth.
- Set Polianthes outdoors once the soil has warmed and nighttime temperatures remain above 60°F (15.6°C)
- In mild-winter regions, they can be grown outdoors year-round.
Planting and Spacing Polianthes–Tuberose
- Set tubers 3 inches (7.6cm) deep.
- Space Polianthes 6 inches (15cm) or more apart.
How to Water and Feed Polianthes–Tuberose
- Once leaves appear, water Polianthes regularly.
- Work a balanced fertilizer into the soil at planting time.
- Feed plants every two weeks until flowers fade; use a mild all-purpose fertilizer.
- Tubers may survive Zone 7 winters with an extra-heavy layer or coarse mulch such as evergreen boughs, salt hay, or pine needles.
- To overwinter tubers indoors, gradually withhold water as the leaves begin to turn yellow; lift them from the garden after the first light frost, allow them to dry in a warm shaded place, then cut off the foliage. Store them in dry peat moss or vermiculite in a cool (65°C), dry place over winter.
Polianthes–Tuberose Pests and Diseases
- Polianthes is usually not bothered by insect pests or diseases.
- Propagate Polianthes by separating offsets in spring.
- Sow seed at about 70°F (21°C).
Polianthes–Tuberose Varieties to Grow
- Polianthes tuberosa, tuberose. Grows 2 to 4 feet (.6-1.2m) tall with rosettes of basal leaves; bears erect spikes of 20 or more waxy white 1- to 2.5-inch flowers that are intensely fragrant. Cultivar ‘The Pearl’ produces fragrant, semidouble, or double creamy white flowers. Cultivar ‘Mexican Single’ grows to 42 inches (104cm) tall.