The ‘Spider Orchids’
Some of the most remarkable of the Australian Orchids are the Caladenia Orchids .
Commonly called ‘Spider Orchids’ these are a terrestrial orchid some with flowers that do remind us of spiders. However within the genus, flower form does differ greatly.
With nearly 200 species identified, the vast majority are from Western Australia. However some wonderful species are also found in the Eastern States.
If you consider the intricacy of the flowers, along with great colours, Caladenia species stand up to some of the best in the world. They may lack size, however they are yet another beautiful Australian Orchid.
Over the years a number of species from New South Wales and Victoria in particular have come close to extinction. Mainly due to urban development and grazing. C. concolor is one, found only in one reserve near Albury. A number of other species are also under threat.
Caladenia are a terrestrial orchid and with such a wide spread distribution it is essential that you obtain growing notes from the nursery you purchase spider lilies from.
Some species are pollinated by male Thynnid wasps, others by bees.
Important Warnings
- Poisonous/Toxic:
Caladenia are not generally listed as poisonous garden plants, but as with any ornamental orchid they are grown for display rather than consumption. Avoid eating any part of the plant. - Invasive/Weed Potential:
These are not invasive plants and are more often threatened than weedy. Many species are protected and have strict conservation status. - Legal/Conservation Note:
Native terrestrial orchids, including many Caladenia, are protected in the wild in all Australian states and territories. It is illegal to collect plants or tubers from the bush; always obtain stock from reputable, licensed nurseries.
Planting Caladenia Orchids
(Because Caladenia needs vary by species and region, always follow detailed notes from the specialist nursery supplying your plants.)
When to Plant:
- Plant dormant tubers in late summer to early autumn so they can establish roots before winter and flower in spring.
Where to Plant:
- Best grown in pots or baskets rather than open garden beds, where conditions can be more carefully controlled.
- Position in bright, filtered light or dappled shade, mimicking open woodland conditions.
Soil:
- Use a free‑draining, slightly acidic mix suited to Australian terrestrial orchids, often based on sand with some organic material.
- For Caladenia, growers commonly use a dry, sandy mix that drains well in winter yet retains some moisture in autumn and spring.
Spacing:
- Plant tubers with enough space so each plant has good airflow and room for offsets; in pots, space a few tubers evenly across the surface rather than crowding.
Container/Pots Suitability:
- Caladenia are very well suited to container growing, which allows you to adjust watering and light, and to protect pots from extreme summer heat or heavy rain.
- Use deep pots or orchid tubes with ample drainage holes.
Ongoing Care for Caladenia Orchids
Watering:
- Water sparingly until new shoots appear, then increase watering during active growth and budding.
- Keep the mix evenly moist in autumn and spring, but never waterlogged; reduce watering as flowering finishes and stop once plants go dormant
Amendments and Fertiliser:
- Native terrestrial orchids do not like heavy fertilising.
- Many growers add only a small amount of native‑safe, low‑phosphorus slow‑release fertiliser or a pinch of blood and bone to the mix at repotting, plus very dilute liquid feed during active growth if needed.
Pruning and Deadheading:
- Remove spent flower stems once seed has matured (if you are not collecting seed) and tidy away old, dead leaves after they dry off.
- Do not cut back green tissue while it is still feeding the tuber.
Overwintering:
- Most Caladenia are naturally cool‑climate orchids and tolerate light frosts if the pot is well drained.
- Keep pots on the dry side during dormancy over summer, protecting tubers from excessive heat and direct sun on the container.
Propagation
- By Tubers:
- Established plants produce replacement tubers and sometimes small offset tubers.
- These can be divided and potted individually when dormant, usually every few years, following specialist advice for the species you are growing.
- From Seed:
- Caladenia seed germination is highly specialised in nature and relies on specific mycorrhizal fungi.
Pests and Diseases
- Common Issues:
- Rot of tubers or roots in poorly drained or overwatered mixes.
- Snails, slugs and some caterpillars can damage new shoots and flowers
- Prevention & Management:
- Ensure a very free‑draining, appropriate mix and careful watering cycle.
- Protect pots from snails and slugs using barriers or pet‑safe baits, and inspect regularly for chewing damage.
Design Ideas
- Enjoy Caladenia orchids up close by growing them in pots placed at eye level when in flower, so you can appreciate the detail of each bloom
- Group pots of different species together to show the range of flower shapes and colours in the genus.
- Use photos and labelled pots as an educational feature in native gardens to highlight the conservation importance of Australian terrestrial orchids.
Caladenia Orchids – Species
- Caladenia splendens is probably the largest flowering of the species.
- C. drummondii would be one of the smallest flowering.
- Caladenia polychroma or ‘Joseph’s Spider Orchid’ is very pretty species well worth looking for.
- C. concinna is found on the Southern Plains of NSW.
- C. magniclavata is from Western Australia.
- C. tentaculta is from South Australia and Victoria.
- A little different is Caladenia latifolia or ‘Pink fairy orchid’ (Picture Right)
- C. gracilis is commonly called the Musky Caladenia.
- C. pusilla is a diminutive species.
- C. carnea var. carnea is known as ‘Pink Fingers’
- C. congesta is the Black tongue Caladenia
- C. catenata is commonly called White Fingers’.
- C. transitoria is the Eastern Bronze Caladenia.
Many species that were naturally found in urban areas or areas widely used for agriculture are now endangered due to loss of habitat.
Of the 80+ species most are found in Western Australia but some are spread across NSW and Victoria as well,.