Rossioglossum williamsianum

Also known as: William's Rossioglossum or Odontoglossum grande var. williamsianum Rossioglossum williamsianum h.v. pachecoi in the subfamily: Epidendroideae

Native to: Guatemala Honduras

General Information

William's Rossioglossum is a medium to large sized sympodial cool to warm growing epiphytic orchid belonging to the sub family Epidendroideae native to Guatemala and Honduras. It is named after the Englsih Orchid Nurseryman in the 19th century.

Plant Description

Sympodial. Grows to 50cm. Each new growth has numerous leathery arching, elliptic leaves that grow to 7-40cm long. Pseudobulbs grow to 4-10cm

Substrate(s)

• Coarse
• Medium
• Bark
• Charcoal
• Spaghnum Moss
• Perlite

Care Notes

These orchids like to be kept on the dry side, but may need to be watered daily during warm weather, and prefer a well draining mix or also do well mounted, provided they can be watered regularly.

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 high elevations. Rainfall ranges from 5mm to 175mm per day, heaviest in September and lightest in February. Humidity ranges from 63% to 81%, highest in October and lowest in March. Temperature ranges from 15C to 30C, highest in April (19C to 30C) and lowest in January (15C to 25C).

Watering

These orchids are sensitive to excessive watering and should only be watered when they look thirsty. Water infrequently and ensure that the roots are dry before watering. Keep an eye on them especially during hot weather as overwatering can lead to rot, whereas underwatering may result in wilting or shriveling, which while unattractive, will not kill the plant.

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.

Use balanced fertiliser during Spring and Summer. 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 very well in baskets or suspended pots This plant does well mounted. Repotting is best done annually.