Thai Onion Plant

Crinum thaianum

A bulb the size of an onion with long ribbon leaves that reach the surface and drift along it. Undemanding — its only real requirement is room.

Light: low–high
Difficulty: easy
Height: 60 – 200 cm (24 – 79 in)
Temperature: 15 – 32 °C (59 – 90 °F)

Leaf colour: green, white markings
Plant type: rosette
Growth rate: medium
Tolerates light: low – high
pH: 5 – 8
Carbonate hardness: 2 – 12 °dKH
General hardness: 0 – 30 °dGH
Placement: background, midground +1 background, midground, specimen
Propagation: seeds, division +1 seeds, division, daughter plants
Grows emersed: no

Appearance

Broad green ribbon leaves rise from a large pale bulb in a rosette. In the wild the plant grows in flowing streams with the leaves streaming in the current, and it does the same in an aquarium. An older plant may send up a flower stalk with a fragrant white lily flower above the water.

Keeping

Easy and long-lived, with the usual bulb rule: leave the upper part of the bulb above the substrate, or it rots. It is a heavy root feeder and wants a nutritious substrate. Light can be dim or bright; carbon dioxide is optional. The real limit is space — the leaves are long, and in a small tank they lie across the whole surface.

Placement

The back or middle of a roomy tank, alone. Plant it where the leaves can stream away from the front glass rather than across it.

Propagation

By daughter bulbs beside the main one: separate them once they have their own roots and leaves. Plants that flower can also set seed.

Water conditions match

The water suits 1007 of 1249 species in the catalogue — these are the ones people look up most often.

Swordtail Guppies Cobra Guppy Blood Red Molly Butterflyfish Red Zebra Cichlid Julii Corydoras Red-finned Parotocinclus Gastromyzon monticola Egg-shaped Goldfish Flame Tetra Gardner's Killifish African Tetra Kenyi Cichlid Cuckoo Catfish Golden Swordtail Hypsolebias picturatus Common Zacco Labeo Bicolor Gambusia Flying barb Gastromyzon scitulus Albino Zebra Danio Geophagus Brokopondo Zebra Mbuna

Will eat this plant

These species damage plants, especially when their diet is short of vegetable food.

Bengal Loach Zebra Loach Burmese Border Loach Emperor Botia Spined Loach Marbled Headstander Pellegrin's Leporinus Leporinus striatus False Black Tetra Common Metynnis Mylossoma duriventre Red Whiptail Catfish Molly sphenops Balloon Molly Lyretail Molly Marble Molly Hi-Fin Platy Hawaii Platy Blue Platy Pintail Platy Black Platy Chocolate Molly Moonlight Gourami Melanotaenia parva

Will uproot it

These species dig through the substrate and pull rooted plants out.

Marble Loach Peacock Eel Forktail Loach Guntea Loach Long-nosed Loach Horseface Loach Pearlscale Black Moor Goldfish Shubunkin Painted Pleco Featherfin Synodontis Reddish Mystus Catfish Blue Acara Aulonocara maylandi Aulonocara multicolor Aulonocara Orchid Geophagus altifrons Geophagus winemilleri Pearlscale Cichlid Pearl Cichlid Redbelly Cichlid Red-spotted Cichlid Chuco godmanni Haplochromis philander Red Chromide Jack Dempsey cichlid

Matching water does not mean the fish will leave the plant alone.

The same plant with a different look: light, water and care are shared with the species.

Other varieties: Crinum thaianum Topf

Scientific and other names, conservation status

Crinum thaianum: J.Schulze
Family: Amaryllidaceae
Conservation status: EN

Thai Onion Plant

Tank conditions

Care and keeping