Just love dendrobiums

Display from the 2022 Autumn Orchid Show.

I often get asked what my favourite flower is. And that is a very hard question to answer. Then Wednesday afternoon some of my Cooktown Orchids had come into full and honestly it is very hard to beat the beauty of these flowers.

The Cooktown Orchid or Dendrobium bigibbum would be the best known and most colourful of Australia’s Orchid species. It can be found growing naturally in the forests of Queensland north from around Cooktown to the Cape York Peninsular and the islands of Torres Strait.

The Cooktown Orchid has purple flowers are borne on long stems with as many as ten flowers on each.

There are many new colour variations of the Cooktown Orchid from pure white my favourite to many bi-colours. The flowers are best described as large and blooming during Autumn and Winter.

At this time of year the Cooktown Orchids making a great floral display.

Of all the flowering plants found in the world the Orchid would have to be the most beautiful. Yet at the same time this spectacular flowering plant gets a bad rap by many gardeners as to being too hard to grow.

As with all plant species some are for the dedicated enthusiast and other are perfect for those that have been cursed with brown thumb.

The Dendrobium Orchids are among the most commonly sold Orchids within the retail trade. Like a lot of other Orchids, Dendrobiums are Epiphytes, or Air Plants. These Orchids have well developed water storage organs that are called Pseudo Bulbs which are often called canes for their upright leafy appearance.

Dendrobiums are separated into two main groups Hard Cane and Soft Cane. Hard Cane Dendrobiums have tall Pseudo Bulbs that are very thin and their foliage is generally darker in colour than the Soft Caned Dendrobiums.

Hard Cane Dendrobiums are evergreen and often keep their leaves for many years before shedding their leaves. The Cooktown Orchids is part of the Hard Cane Dendrobium Orchid sub group.

Dendrobiums will grow quite happily in glasshouses or shade houses, depending on variety. Most Dendrobiums prefer temperature in the range of 18-35 °C highs during the day and 8-15 °C lows at night, but they will tolerate higher temperatures if the humidity and air circulation are good.

They require sufficient light for healthy growth and flower production. In a shade house situation, shading with 50-70 per cent shade cloth is ideal. Plants receiving adequate light should be naturally erect without the need for much staking, and be of medium to olive green in colour.

They should be watered thoroughly and kept evenly moist while in active growth. Allow them to dry between watering after the growth is mature as indicated by terminal leaf.

Hard Cane Dendrobium will require fertiliser on a regular basis. Fortnightly or weekly fertilising is preferred through the growing period. It is best to fertilise at half strength. Good results may be obtained by using a balanced fertiliser with NPK of 12-12-12 all year round.

Dendrobiums are like most orchids, enjoy moist air, requiring a minimum of 50-60 per cent humidity in the immediate vicinity of the plant. Humidity can be increased by misting during periods of hot weather, or by placing plant pots on moistened trays of pebbles.

Dendrobiums need to be repotted every 2 to 3 years depending on the Potting Mix used, as some mixes will break down quicker. The Potting Mix should consist of medium Pine Bark with Perlite, Charcoal, or Polystyrene Balls added to provide good aeration of the mix. When repotting, allow enough room for two years of growth.

One question that is often asked is when should the Hard Cane Dendrobiums be divided? I have always followed rule that you only divide the Hard Cane Dendrobiums when the divided plants are in clumps of three to five mature pseudo bulbs.

Hard Cane Dendrobiums are really worth a try for gardeners wanting to enjoy Orchid growing. And today and tomorrow these simply stunning Orchids are on display at the Rockhampton Orchid Society’s Spring Orchid Show

The Rockhampton Orchid Society will conduct their Autumn Orchid Show at the Frenchville Sport Club. Come along and see massed displays of beautiful Spring flowering orchids. Plants and potting materials will be on sale as well as potting demonstrations will be given throughout the show. If you have any orchids you require advice about, please bring them along to the show for the resident Plant Doctor to help.

The show will open on Saturday 15 September from 8am to 4pm and on Sunday 16 September from 8am to 2pm. Admission to the show is $5 for adults and children free.