Oncidium wentworthianum

Also known as: Wentworth's Oncidium or Oncidium hagsaterianum in the subfamily: Epidendroideae

Native to: Chiapas - Mexico Guatemala

General Information

Wentworth's Oncidium is a medium sized sympodial cool to warm growing epiphytic orchid belonging to the sub family Epidendroideae native to Mexico and Guatemala. It is named after the English Count-Orchid Enthusiast in the 19th century.

Plant Description

Sympodial. Grows to 43cm. Each new growth has numerous leathery leaves that grow to 1.5-35cm long. Pseudobulbs grow to 7.5-12.7cm

Substrate(s)

• Coarse
• Medium
• Bark
• Perlite

Care Notes

These orchids like to be watered regulary, especially during warm weather, and prefer a well draining mix or also do well mounted, provided they can be watered daily or even many times a day.

These are quite a forgiving orchid, there are no special requirements to get this orchid to flower, just good care and consistent conditions. Larger plants may be more fussy and can react poorly to change; a poorly timed repotting, a pest infection or an unusually hot day can set them back for a couple of years. However, even plants that have been treated poorly can thrive, and if they are set back they often recover much stronger then they would otherwise be.

Climate

Grows at low to high elevations. Rainfall ranges from 38mm to 508mm per day, heaviest in September and lightest in March. Humidity ranges from 82% to 90%, highest in January and lowest in April. Temperature ranges from 11C to 23C, highest in May (15C to 23C) and lowest in January (11C to 16C).

Watering

These orchids prefer a wet-dry cycle between waterings, they should be watered frequently but only when the moisture is approaching dryness, where the pot feels light and/or the media looks dry. Keep an eye on mounted orchids in warm weather as they may dehydrate quickly.

Keep moisture levels up during hot weather as the plant is prone to dehydration

Fertiliser

Apply liquid based fertiliser per recommended directions. They can benefit from a high phosphate fertiliser leading up to flowering season, followed by a high nitrogen fertiliser when new growth appears, and a balanced fertiliser in other times. These orchids can also tolerate slow release fertiliser applied 1-2 pellets per cup (250ml) of media.

Apply fertiliser regularly at half strength year round. Use a high Nitrogen fertiliser during Spring and Summer. Use a high Phosphorous fertiliser during Summer.

Potting

These plants are quite forgiving and will do well repotted ever 2-3 years. The mix should be coarse, well draining, and allow space for air to move and for roots to grow. 

Alternatively, these plants will also do well mounted to tree fern or cork slabs, or mounted to trees.

Best time for repotting or mounting the orchids is the end of winter when new growths start to appear. Avoid repotting during hot weather,

Use water retentive media such as moss to prevent roots from drying out quickly This plant does well mounted to Tree trunks, Fern slabs or Cork slabs. Repotting is best done annually.