Oncidium cultratum

Also known as: The Knife or Oncidium formosissimum Oncidium jamiesonii Oncidium cuencanum in the subfamily: Epidendroideae

Native to: Ecuador

General Information

The Knife is a sympodial cold to cool growing epiphytic or terrestrial orchid belonging to the sub family Epidendroideae native to Ecuador.

Plant Description

Sympodial. Grows to 30cm. Each new growth has numerous leathery erect leaves that grow to 2.4-24cm long. Pseudobulbs grow to 3-6cm

Care Notes

These orchids have a fine root system that can quickly die back if left dry for too long, but also does not like to be kept wet, so water regularly but ensure that the mix is dry before watering. 

Climate

Grows at high elevations. Rainfall ranges from 23mm to 109mm per day, heaviest in October and lightest in January. Humidity ranges from 73% to 77%, highest in October and lowest in January. Temperature ranges from 5C to 19C, highest in May (8C to 19C) and lowest in February (5C to 16C).

Fertiliser

These plants do well with slow release fertiliser at the rate of 2-3 pellets per cup (250ml) of media. Additional fertiliser during the growth period may be beneficial, but not necessary.

Potting

These plants can be sensitive to repotting though should not require repotting regularly. Repotting should be done when the mix has broken down to the point that it doesn't absorb water or holds onto water for far too long, usually the plant shows a decline in growth as well.

The mix should be free draining, with a blend of 30% inorganic ingredients such as coarse sand, gravel or perlite, mixed in with about 70% organic ingredients such as peat, leaf litter or decomposed bark. Avoid commercial potting mixes as they can vary wildly and may contain "wetting agents" that can hold onto water for loo long, causing rotting and stunted growth.