Cypripedium macranthos

Also known as: The Large Flowered Cypripedium or Cypripedium macranthum h.f. alba Cypripedium macranthos h.v. album Cypripedium macranthos var. album Cypripedium macranthos var. hotei-atsumorianum Cypripedium macranthos var. taiwanianum Cypripedium macranthos h.f. album Cypripedium macranthos var. maximum Cypripedium macranthos f. rebunense Cypripedium thunbergii Cypripedium macranthos nothof. alboroseum Cypripedium macranthos nothof. albostriatum Cypripedium macranthos nothof. flavoroseum Cypripedium rebunense Cypripedium macranthos var. albiflorum Cypripedium macranthos h.f. flavo-roseum Cypripedium macranthum h.v. speciosum Cypripedium macranthum h.v. rebunense Cypripedium macranthos f. albiflorum Cypripedium macranthos f. vulgare Cypripedium macranthum h.v. hotei-atsumorianum Cypripedium macranthum h.v. ventricosum Cypripedium macranthum h.f. rebunense Cypripedium thunbergii f. albiflorum Cypripedium calceolus var. rubrum Cypripedium speciosum var. albiflorum Cypripedium macranthon Cypripedium macranthum Cypripedium macranthos h.v. hotei-atsumorianum Cypripedium macranthos h.v. taiwanianum Cypripedium macranthos var. speciosum Cypripedium macranthos var. rebunense Cypripedium macranthos var. flavum Cypripedium speciosum Cypripedium macranthos var. atropurpureum Cypripedium neoparviflorum in the subfamily: Cypripedioideae

Native to: Heilongjiang - China Japan Liaoning - China Shandong - China

General Information

The Large Flowered Cypripedium is a large cold to cool growing terrestrial orchid belonging to the sub family Cypripedioideae native to China and Japan.

Plant Description

Grows to 50cm. Each new growth has numerous erect elliptic, oblong shaped leaves that grow to 5-15cm long. Pseudobulbs grow to 25-50cm

Substrate(s)

• Coarse
• Spaghnum Moss
• Sand

Care Notes

These orchids grow on the forest floor so are used to rich soil containing plenty of organic matter that is always moist (but not always wet), and prefer constant conditions in terms of humidity, temperature and water supply. They may not be as forgiving as epiphytes in regards to sudden changes in growing conditions so it is wise to ease them into new conditions over a the space of a few days, and repot as infrequently as possible.

Keep an eye on the plants condition regularly as they can decline suddenly if the conditions are not just right. It is more important to keep water supply constant rather than frequent - overwatering often causes rot which can quickly set in, especially in warmer conditions.

These can be grown in shady, moist areas in the garden, supplied they have protection from abrupt changes caused by the elements, e.g. dry winds, frost etc. Being grown around companion plants such as ferns and bromeliads will help build and retain the humidity they require throughout the year.

Climate

Grows at low to high elevations. Rainfall ranges from 4mm to 107mm per day, heaviest in August and lightest in January. Humidity ranges from 50% to 81%, highest in August and lowest in March. Temperature ranges from -14C to 22C, highest in July (13C to 22C) and lowest in February (-14C to -13C).

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.

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 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.