Dendrobium rex

Also known as: The Kingly Dendrobium or The Golden King Orchid in the subfamily: Epidendroideae

Native to: Queensland - Australia

General Information

The Kingly Dendrobium is a small to medium sized sympodial cool to warm growing epiphytic, lithophytic or terrestrial orchid belonging to the sub family Epidendroideae native to Australia.

Plant Description

Sympodial. Grows to 105cm. Each new growth has numerous leathery rigid leaves that grow to 25cm long. Pseudobulbs grow to 80cm

Flowers

Numerous blossoms appear during Spring

Blooming Season

• Spring

Substrate(s)

• Coarse

Care Notes

This orchid goes into a dormancy phase during winter, during this phase it is best not to provide water unless the plant is starting to look thirsty. The lack of water increases the chance of flowering in spring, and also reduces the likelihood of any rot forming. Do not resume watering until new growth has appeared and is growing strongly.

Often a period of intense growth occurs after dormancy. During this time the amount of light, water and fertiliser the plant receives will directly impact the amount of growth that occurs during this time, and in the case of seedlings, will reduce the time required to reach maturity.

It's recommended to heavily reduce the water amount at the middle to end of autumn to trigger dormancy. Leaves on older bulbs will begin to drop during this time while the newer bulbs continue to mature until terminal leaves appear at the tip of the pseudobulbs.

Repotting can be done any time of the year though it's best to do it in early spring when new growth is appearing as this also means new roots will appear to help the plant anchor into the new media and offset any damage to established roots during the repotting process.

 

Climate

Grows at low elevations. Rainfall ranges from 41mm to 127mm per day, heaviest in July and lightest in February. Humidity ranges from 54% to 67%, highest in August and lowest in May. Temperature ranges from 5C to 28C, highest in June (16C to 28C) and lowest in January (5C to 16C).

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.

During Summer, be sure to keep media moist. Keep moisture levels up during hot weather as the plant is prone to dehydration

Fertiliser

dormant-medium-demand-orchid Be sure to flush out excess fertiliser by running water through the media regularly year round. 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. Repotting is best done after the growing season when the plant has died back.

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.