Bulb · Asparagaceae
Tuberose
Polianthes tuberosa
Give it full sun and fast-draining soil, and tuberose fills late summer evenings with its famous scent.
Full sun
Every 5–10 days
55–84°F · 13–29°C
90–120 days
Overview
Tuberose is grown for one thing above all: its perfume. The tall spikes open creamy white flowers in late summer, and the scent carries well after dark, which is why it has long been a favorite for cut bouquets and night gardens. Despite the name, it has nothing to do with roses. It's a tuberous-rooted relative of the agaves, native to Mexico and grown there for centuries.
The plant runs from 2 to 3 feet (61 to 91 cm) tall, sending up narrow grassy leaves and then a flower spike that keeps opening blooms over several weeks. It's a tender perennial that thrives where summers are warm and winters are mild. In colder gardens, growers lift the tubers in fall and store them, much as you would dahlias.
Tuberose asks for warmth, sun, and soil that drains. Plant the tubers in spring, water them through the heat of summer, and ease off as the foliage yellows in fall. The one thing it won't forgive is wet feet, so heavy, soggy ground is the fastest way to lose it.
Care
The short version: full sun, organically rich soil that drains fast, and steady moisture through the summer growing season. Feed monthly, ease back on water as the leaves yellow in fall, and divide the clumps every few years to keep the blooms coming.
Light
Tuberose wants full sun to bloom its best, ideally a spot that gets sun for most of the day. It will put up with a little afternoon shade, but too much shade trades flowers for floppy, leafy growth.
Water
Keep the soil evenly moist through the summer growing season, letting the top half dry between waterings so the tubers never sit wet. A drink every 5 to 10 days suits most gardens. As the foliage yellows in fall, taper off and let the plant slide into dormancy.
Soil
Plant in rich, well-drained loamy or sandy soil, which matters more than anything else for this plant. It takes a wide pH range, anywhere from 6.0 to 8.0, so most garden beds work as long as the water moves through and never pools.
Temperature
Tuberose grows happily in warmth, roughly 55°F to 84°F (13°C to 29°C). It's tender and won't survive frost, so in cold-winter areas the tubers come up and go into storage before the first freeze.
Humidity
Ordinary outdoor humidity suits it fine, with no number to chase. The plant cares far more about warmth and drainage than about moisture in the air.
Feeding
Feed monthly through spring and summer while the plant is in active growth, using a balanced general-purpose garden fertilizer. That steady feeding fuels the tall spikes and keeps the blooms coming.
Pruning
There's no routine pruning to do. Cut spent flower spikes once they fade, and leave the foliage alone to die down naturally in fall so the tuber can bank energy for next year's bloom.
Repotting
Tuberose doesn't need repotting so much as dividing, which keeps it vigorous. Split crowded clumps every 2 to 3 years when you see many offsets, declining flowers, or tubers pushing up to the surface.
Size & spacing
24–36 in (61–91 cm) tall
When to plant
Tuberose runs on a warm-season clock and has no tolerance for frost. Start tubers indoors in early spring, set them out once the cold has passed, and the spikes open from August into September, scenting the garden through late summer.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Early spring, started in containers before last frost
- Plant: Spring after the last frost date, planted 2 inches deep and 6-8 inches apart
- Harvest: August to September (late summer to early fall)
Hardiness
USDA hardiness zones: 7–10
Temperature: down to -18°C
Troubleshooting
Most tuberose trouble starts underground or shows up as a season with all leaves and no flowers. Catch the early signs and the fix is usually simple. Match what you see below, then act before the tuber suffers.
Mushy tubers and foliage that yellows and flops over
This is tuber rot, and it almost always traces back to soil that stays too wet. Tubers planted deep in heavy ground sit in trapped water and turn soft from the inside. Lift the plant, cut away any mushy, foul-smelling tissue, and replant only firm tubers in sandy or loamy soil that drains fast.
Fix:
- Stop watering and improve drainage
- Lift affected tubers and discard rotted ones
- Replant healthy firm tubers in well-drained sandy or loamy soil
Plenty of leaves but barely any bloom after year one
Tuberose loses its bloom when crowded clumps fight over the same patch of soil, or when the foliage gets cut back before the tuber has banked its energy. Divide the clump every 2 to 3 years and let the leaves die down on their own each fall. Keep only the largest tubers, since small offsets need a season or more before they flower.
Fix:
- Divide clumps every 2-3 years
- Allow foliage to die down naturally before lifting
- Replant only the largest tubers for reliable bloom
Twisted new growth crawling with tiny insects
Aphids gather on the soft new shoots and suck the sap, which leaves the growth puckered and sticky with honeydew. Thrips, spider mites, and scale can pile on too. Blast them off with a strong jet of water first, and reach for insecticidal soap only if they keep coming back.
Fix:
- Spray off with a strong jet of water
- Apply insecticidal soap if needed
Toxicity
Tuberose is a safe plant to grow around pets, livestock, and children. It carries no known toxins and never appears on the ASPCA's toxic plant lists, so a stray nibble is nothing to fear. The only thing to mind is the sap, which can mildly irritate sensitive skin, so rinse your hands after cutting stems.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Tuberose is safe around cats and doesn't appear on the ASPCA toxic list. A curious nibble of leaf might cause a little mild stomach upset, as any unfamiliar plant can, but nothing serious.
Dogs None
Dogs can share a garden with tuberose without any worry. There's no toxin to fear here, so a chewed leaf or flower won't do harm.
Horses Safe
Horses are in no danger from tuberose. It carries no known toxic compounds and isn't flagged as a problem for grazing animals.
Rabbits Safe
Rabbits can browse tuberose foliage safely. The plant holds nothing harmful to them.
Livestock Safe
Cattle, goats, and sheep face no risk from tuberose, which has no toxicity on record for farm animals.
Birds Safe
Birds are safe around tuberose, whether they peck at the plant or just share the space.
People Safe
Tuberose is safe for people, and the flowers are prized for their scent. The only real catch is the sap, which can mildly irritate sensitive skin, so rinse your hands after handling cut stems.
The flowers are intensely fragrant; the strong scent may be overwhelming to some people in enclosed spaces.
Varieties
A handful of tuberose forms turn up most often, sorted mainly by their flowers and fragrance. These are the ones worth knowing by name.
The Pearl
A popular double-flowered form whose fully petaled, waxy white blooms give it the look of a small gardenia.
Mexican Single
A single-flowered form widely held to carry the strongest fragrance of any tuberose.
Sensation
A fragrant selection set apart by its soft pink-tinted flowers.
Marginata
A miniature form grown as much for its variegated foliage as for its bloom.
How to propagate
Tuberose is easiest to multiply by lifting and splitting its tubers, the same job that keeps an aging clump flowering well.
Offsets & pupsEasy
Spring, when lifting and dividing dormant tubers · Largest offsets may bloom the next season; small offsets often take a year or more to reach blooming size
Tuberose multiplies on its own by sending out offsets around the parent tuber. Lift and split them in spring while the tubers are dormant. The biggest offsets often flower the very next season, while the smaller ones need a year or more of growing on before they reach blooming size, so it pays to keep them and wait.
DivisionEasy
Spring, every 2-3 years · One or more growing seasons before reliable flowering
Dividing crowded clumps every 2 to 3 years in spring keeps the planting vigorous and blooming well. Separate the tubers and replant only the largest for the best show. Expect a growing season or more to pass before the divisions settle in and flower reliably.
SeedModerate
Spring · Several years to reach flowering size
Tuberose can be grown from seed sown in spring, but it's the slow road. Seedlings take several years to reach blooming size, far longer than offsets, so most gardeners stick with dividing tubers instead.
Myths
Tuberose is a type of rose.
The name fools almost everyone, but tuberose has no kinship with roses at all. It's a tuberous-rooted member of the Asparagaceae family, known as Polianthes tuberosa and also classified as Agave amica. The name comes from its swollen tuber, drawn from the Latin tuberosa, not from any flower.