Grammatophyllum speciosum or tiger orchid is the largest orchid in the world and one of the largest epiphytes in general.
The pseudo-bulbs are up to 2.5 m high and the inflorescence up to 3 m high.
The pseudo-bulbs can weigh hundreds of kilos and even more than a ton. A specimen of two tons was exhibited in 1851 at an exhibition at Crystal Palace, London.
It is not exactly the easiest orchid to grow because of the space and amount of sunlight it needs.
In the wild they grow epiphytic on sturdy trees and even as lithofyts. Like cactus and succulents, they have a special metabolism making them resistant to thermal shock and, to a lesser degree, hydric shock. This allows them to grow in relatively dry plains or directly on the ground.
The pseudobulbs are cylindrical and are 2.5 m tall. They form dense clusters that may weigh hundreds of kilos. The pseudo-bulbs are erect, yellowish with age, ribbed and noded. They form numerous aerial roots.
They are surrounded by leafless and leaf-bearing sheaths. The leaves are linear or oval, blunt or pointed. The leaves are scattered on the basal leaf sheath.
The inflorescence is up to 3 m tall and bears about 80 flowers of 12.5-20 cm. The flowers are yellow with brown or dark red spots. They are waxy, fragrant and bloom in turn. The lower flowers have no lip.
The flowering lasts about 2 months but the plant flowers only when it has reached a certain size and has enough backbulbs. And even then it still flourishes very irregularly, every 2-4 years.
New Guinea, Indonesia, Malaysia and the Philippines.
This epiphyt grows mostly on forks and trunks of large trees in clearings in the lowland tropical rain forest where it enjoys a lot of sunlight. Sometimes it grows as lithofyt on the ground.
Grammatophyllum: from the Latinized Greek gramma (letter) and phyllum (leaf) which describes the pattern on the flower.
Speciosum: from the Latin speciosus (beautiful, exceptional).
Grammatophyllum cominsii, Grammatophyllum fastuosum, Grammatophyllum giganteum, Grammatophyllum macranthum, Grammatophyllum pantherinum, Grammatophyllum papuanum,
Grammatophyllum sanderianum, Grammatophyllum wallisii, Pattonia macrantha
Diurnal: 24-30 °C
Nocturnal: 13-16 °C
Tolerates temperatures up to 38 °C and down to 7 °C.
As much direct sunlight as possible.
During the growing season (spring to autumn) should be watered regularly but the substrate must not be permanently wet.
In winter, let the substrate dry out before watering again.
Prefer rainwater or non-alkaline water at room temperature. Do not use water from a water softener, because it contains too much salts.
Needs less air humidity than most of the other orchids.
This orchid can be grown in pots, hanging baskets or mounted on a tree stump. But because it grows very large and heavy, a hanging pot will be difficult. When grown in pots, you must weigh the pot down with rocks to keep its balance.
Use sphagnum moss or medium sized fir bark.
Must be fertilized abundantly during the growing season.
Repot in the spring when new roots are formed. This allows the roots to develop well and settle for the winter.
Here you can see how the Brooklyn Botanical Garden repotted their specimen: Repotting of tiger orchid.
When repotting the plant in the spring, you can divide it. Keep a minimum of 3 pseudo-bulbs per plant.