Growing it

Growing Wollemi Pine - a rare rainforest emergent species

There has been worldwide interest in and demand for the Wollemi Pine for horticulture. As part of a strategy for Protecting it, research into its horticultural development and commercial propagation has allowed the plant to be available. This strategy is to ensure that it exists in cultivation so that people can learn about this interesting species while helping to conserve it. Plants have been available from Botanic Gardens Shops at the Royal Botanic Garden, Sydney, the Australian Botanic Garden, Mount Annan, and the Blue Mountains Botanic Garden, Mount Tomah or on-line or from selected nurseries in Australia since 1 April 2006.

So far, the plant is proving to be an especially good pot plant and can be grown in many garden situations. Be aware that this is a rare emergent rainforest tree, and although it has survived in the wild over many millennia, some growing situations are better than others.

In general, the plants need some protection from full sunlight when they are young and they do best where the roots have a cool root run. The best example of a cultivated Wollemi Pine can be found behind the Visitor Centre at the Australian Botanic Garden. This tree, planted in September 1998, has been well-watered and is protected on the southern side of the building, in company with, but not competing with, other plants. The tree is well over 7 metres tall and is covered with both male and female cones. Like plants in the wild, the tree is beginning to produce multiple branches from the base.

Relatively few seeds are produced in the wild and they are extremely difficult to collect (nets need to be set up underneath the trees). Research on seed germination and seedling growth has started and Wollemi Pine seeds are in storage in the NSW Seedbank at Mount Annan (where our scientists are researching the best storage method) and some are also being stored in the Millennium Seed Bank at Kew in the UK.

Mount Annan researchers have developed methods for propagating the Wollemi Pine by cuttings, and commercial propagation is through mass propagation techniques. Interestingly, cuttings taken from the lateral branches produce a delightful prostrate (low growing) plant suitable as a spreading pot plant or ground cover.

Horticultural needs

The Wollemi Pines have been growing from seeds and cuttings under the watchful eyes of the Horticultural Research team at the Australian Botanic Garden since early 1995. Monitoring of plants in both pots and the ground shows that they grow surprisingly fast for conifers.

After an initial slow start, cultivated seedlings grow to about 1 metre after 3 years with a diameter near the base of about 30 millimetres.

On average they are growing around half a metre a year, although growth in the tough conditions in cultivation as well as in the wild is much, much slower (see ecology). They start growing in early spring and really only grow upwards for around two months. After that they concentrate their energy on growing outwards.

This species favours acid soil - in their habitat the pH is as low as 4, and in potted cultivation they favour a pH of less than 6.

Although their habitat soil is naturally low in nutrients, the Wollemi Pines respond well to fertiliser.

Young plants in cultivation need some protection from strong light provided by shade cloth or the shelter of other trees.

Our cool tips for growing Wollemi pines

We find Wollemi pine to be an excellent pot plant - use the best quality potting mix suitable for pot plants
They do grow in the ground in many circumstances, but may be susceptible to common diseases if they are stressed
Give the plants a cool root run
Don�t plant into hot, full sun situations
Give plants some protection from full sun (when they are young sunburn can easily occur - remember they are a rainforest emergent species)
Protect young plants from wind
Filtered or dappled light is good
Do water the plants especially when young - under or over-watering will predispose the plants to disease
Keep competition from other plants to a minimum
Fertilise as for other trees, they are not phosphorus sensitive, but don�t overdo it
Always follow manufacturers' instructions for fertiliser or pest control
Don�t buy wilted plants