Dendrobium racemosum

Also known as: Rat Tail Orchid or Dendrobium beckleri var. racemosum Dockrillia racemosa in the subfamily: Epidendroideae

Native to: Queensland - Australia

General Information

Rat Tail Orchid is a sympodial cool to warm growing epiphytic orchid belonging to the sub family Epidendroideae native to Australia.

Plant Description

Sympodial. Grows to 90cm. Each new growth has numerous erect leaves that grow to 10-20cm long. Pseudobulbs grow to 90cm

Flowers

Numerous fragrant blossoms appear

Fragrance

The orchid is fragrant.

Care Notes

These orchids live in environments that receive constant moisture, high humidity, and are surrounded by other plants such as ferns and mosses which not only attract moisture but compete for it as well.

As a consequence they can be difficult to keep healthy in an artificial environment where a constant balance has to be maintained between providing constant moisture to the roots, but also allowing them to not become soggy and dry quickly as they would in the wild. For this reason it's important to take into account the size of the plant, the health and fragility of the root system, and also think about your watering habits. If you water frequently you can use a media that drains more freely, if you water less reliably you will need to find a media that offers retention and keeps humidity around the roots without being soggy.

Because these orchids like high amounts of water, other plants such as ferns and weeds may start to grow alongside the orchid, whose roots can make the media quite dense, effectively strangling the orchid's roots, it's best to pluck them out before they become a problem. Fungus and bacteria can be an issue as well, but usually are a sign of overwatering, smell the media occasionally to check, and increase airflow, reduce watering, and adjust temperatures accordingly (often bacteria only flourish in warmer temperatures, fungus less so). 

 

Fragrant:

• IsFragrant

Climate

Grows at low to high elevations. Rainfall ranges from 41mm to 460mm per day, heaviest in September and lightest in January. Humidity ranges from 65% to 74%, highest in September and lowest in March. Temperature ranges from 11C to 27C, highest in June (18C to 27C) and lowest in January (11C to 20C).

Watering

These orchids prefer a constant supply of moisture, with a slight drying out between waterings. Saucers can be placed under pots to retain moisture during hot weather, however the saucers should be removed or let to dry every 1-2 weeks to prevent rot. Keep an eye on the plant especially in hot weather and look for cues of under/overwatering and adjust accordingly.

Mist during hot weather Be sure to provide strong air circulation after watering to prevent fungal and bacterial infections from water sitting on leaves.

Fertiliser

These orchids do not need to be regularly fertilised and roots may be sensitive to salt build-up, dying back and therefore impairing the plants growth or even killing it.

If fertilising, use half to quarter of the recommended amount of fertiliser. If they receive fertiliser as part of a collection, be sure to flush out the pots regularly with fresh water and monitor the roots by checking how much resistance is given by the plant when nudged in its pot or mount. If the plant becomes wobbly or loose, repot in fresh mix or rinse the media/mount thoroughly and do not fertilise for at least 3 months.

Apply fertiliser regularly at half strength year round. This plant is sensitive so apply fertiliser sparingly at one quarter recommended strength or less. Use a high Nitrogen fertiliser during Spring and Summer. Use a high Phosphorous fertiliser during Summer. Reduce fertiliser when plant is dormant during Spring.

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,