Garry & Nada Sankowsky, Tolga, North Queensland
In the summer of 1982 we moved from Mt Tamborine to North Queensland to set up a butterfly farm. The land boom was well and truly on and we had difficulty finding a suitable block of land. We finally settled for a rural residential block of 5 acres (2.5 ha) with town water. It has deep basalt soil and is just outside the ‘Golden Triangle’ agricultural region of the Atherton Tableland. The main reason our area was not used for cultivation is that it contains huge numbers of rocks. This is certainly not a disadvantage when planting trees.
Because our initial aim was to breed butterflies, the types of plants that we planted in the first couple of years were heavily biased towards butterfly host plants. We brought two thousand plants with us from Mt Tamborine, which gave us a good start. These were not exclusively plants from the south of Queensland; we had made many trips to North Queensland in previous years and collected numerous northern species.
Our first priority was to set up nursery facilities and a butterfly breeding cage. As well as bush-houses we built a mist house for the propagation of cuttings as this is the way we grow many of our plants. We have found that cutting-grown plants establish and develop much more rapidly than seedlings, and of course seeds are only available at one time of the year for each species whereas cuttings can be taken at any time (in North Queensland).
We wanted a block that was mostly cleared so that we could plant a very wide range of species. We thought (and rightly so, as has been proven) that the dry climate just outside the rainforest belt would enable us to grow plants from many types of habitats and climates. Average rainfall is 1048 mm.
Just at the time we were starting our garden there was a lot of local interest developing in the collecting and planting of North Queensland rainforest species. This encouraged us to expand our range of plants far beyond butterfly host plants.
I feel that I must point out that it would not be possible for someone to do today what we have done. Up until the early 1990s it was extremely easy to collect propagating material from State Forests. The Forestry Department had a simple permit called a Minor Products License that cost about $100 per year and covered all State Forests in a particular region. Under the latest regulations it is so complicated that most people do not bother. As well as this, many of the State Forests have been changed to National Parks, where no collecting is permitted. What was once Swipers Logging Area is now part of the high-altitude Wooroonooran National Park, but by the end of this year there will be no high-altitude rainforest outside of a National Park where collecting can be carried out. This may force a change in the regulations. I certainly hope so or there will be nothing but inbred stock in the nursery trade. Alas! the ‘good old days’ are gone.
The first section we planted was the perimeter as locals referred to this area as Siberia. One corner of the block faces the south-east, which is the source of our prevailing winds, where we have grown a very effective windbreak. The one big mistake that we made was planting some Acacia melanoxylon in the windbreak. These sucker and are so aggressive that they choke out other species. The suckers are now marching into the property next door and present an ongoing problem. Only last week a huge one came crashing down destroying the fence, and putting us to considerable expense to have the top half removed from the neighbouring property.
Because we only had town water we usually restricted our plantings to the wet season. As soon as the monsoon trough activated in January we started planting and continued till about mid-March. We generally planted a thousand or more plants each year.
In the beginning we could not find someone with suitable equipment to cultivate the areas we wanted to plant. We were lucky with the front half of the block because the rocks were not so plentiful and we were able to use a rotary hoe. We tried using a disc plough in the rocks, but this was not very successful. We finally found a local bulldozer owner who had a small D4 and this proved to be the ideal solution. Each year in about May or June we would get an area ripped for the following wet season’s planting. We then purchased sufficient peanut shell to mulch it. At that time peanut shell was only $70 for a 30 metre truck load. One of our plots took seven loads of shell. The peanut shell was then spread over the cultivated ground with a bobcat and left till the wet season. By January the fines in the shell had broken down and the soil underneath was a seething mass of worms and incredibly soft and friable. This enabled us to establish the plants well and eliminated the need for watering them later in the year.
That is, until the rot set in during the early 90s when we had very poor wet seasons and extremely long and hot dry seasons. It was during this period that disaster struck. In November 1992, when we were experiencing extremely hot dry, northerly winds, a fire got out of control on a nearby farm and burnt out a large section of our garden. It was made worse by the fact that there was still a good depth of peanut shell mulch on the ground. Because of our dry climate the peanut shell lasts for about five or six years, making it by far the cheapest and most effective mulch available. By the time it has completely rotted down the ground has long since been covered by the plants and natural leaf drop is providing the rainforest plants with mulch. The smoke was so thick from the burning shell that it was not possible to get close to it to put it out and it burnt for more than twelve hours. We lost about 2000 plants in the fire. Except for two species, most of these could be replaced fairly easily. One was a rather rare Euphorbiaceae plant, Suregada glomerulata, that we have not been able to find again and the other one was as rare as a plant can get. It was collected north of Weipa and was a new genus for Australia, in the Flacourtiaceae family, Hydnocarpus sp. (Possum Scrub G & N Sankowsky 1349). It was a tiny seedling (instantly recognised as something new) germinating in a pile of dirt pushed up by a bulldozer; no more plants can be found, juvenile or adult. It is assumed that the seed would be spread by birds so the adult plants must be within a kilometre or two of where the seedling was found. Luckily it flowered in cultivation and a specimen was lodged with the Queensland Herbarium.
In 1993 we decided to put down a bore to supplement our water supply and were lucky enough to obtain a reasonable flow. Drillers had previously been unsuccessful in locating water in our area and were very reluctant to drill as there are numerous collapsed lava tubes beneath us. These trap the drill and the diamond bits are very expensive to lose. With the bore water we have been able to keep most of our plants alive during the very dry periods that we have had since then.
To eliminate the need to continually water plants all over the garden, we have concentrated the plants that require lots of water into ‘wet zones’ where they can all be watered at once. This has proved very successful and saves a lot of time and water. In these wet zones we grow plants from misty mountain tops, and ferns.
To contain flood waters we dug a gully across out property. This was a dry gully until we put down the bore. We then set up sprinklers in the gully to water two or three times a week. We now have a ferny gully complete with those giants of the fern world - King Ferns. The gully has become one of the wet zones, and delicate and shade-loving plants are planted along it.
Another major problem that we had was wallabies. At first we only had Agile Wallabies. They were bad enough as they flattened many plants, especially ferns, as they hopped around. A few years ago the Mareeba Rock Wallabies showed up and they were a disaster. They feed mostly on plants other than grass, and they ate huge numbers of ferns, orchids and other small plants. Last year we decided to fence them out and built a wallaby proof fence around the block. We are now replanting all the devastated areas.
After
we stopped breeding butterflies we
turned the butterfly breeding cage into a fernery where we now grow a
large
number of native ferns and other delicate plants under 70% and 80%
shade
cloth.
As we wanted to make our garden a proper scientific botanical garden we divided the plantings into grids of about 10m x 10m squares so the plants could be accurately located and recorded. Almost all the plants are from wild collections (not grown from seed or cuttings taken from cultivated plants) and this gives them scientific integrity. Each plant receives a number and is recorded in a database along with the locality where it was collected, which plot number it is in, when it was planted, along with other information such as when it first flowered. There are at present 9379 plants in the database, with probably about 1000 more to be recorded. If you take off 2000 that died in the fire that leaves about 8000 plants in the garden. These are almost all rainforest plants from tropical Australia.
Because of the scientific nature of the plant collection the garden is often used by scientists studying various aspects of botany and plant biology. A few years ago a couple of botanists from Austria spent several weeks here studying the pollinators of Annonaceae plants. We have all but one of the Australian plants in the Annonaceae family. A couple of these we actually discovered. Luckily most of them flower in November and December. Another use for the garden is to supply material for DNA work, as we have almost complete collections of many families.
Many people are reluctant to plant vines. As we wanted as complete a collection as possible (and many vines are butterfly host plants) we collected numerous vines. The main problem with them is if they are planted near small trees they will soon swamp them. If we had a lot more room we could grow them on trellises but as we had a limited space we had to think of another way. We had a number of eucalypt trees growing on the property (E. crebra, E. clarksoniana and E. tessellaris) so we decided to grow the vines up these plants. Each ‘vine tree’ had about 30 – 50 vines planted at its base. From pegs driven into the ground bailing twine was tied to galvanised roofing nails placed about 6 – 8 m up the tree, allowing the vines to go straight up and not twine around the base of the trees. This proved very successful (perhaps a bit too successful as two eucalypts have been killed by the vines) and enabled us to have a large collection of vines.
We
found that some vines do not survive well with competition. They do well for the first couple of years
while the cultivated soil is still loose and the roots of nearby plants
have
not yet invaded. However, after a few
years they fade away. Growing them in
pots was not very successful until we tried the ‘bog method’. This consists of standing the pot in a tray
that has holes drilled in it about 30 – 50 mm from the bottom and
filled with
sand. The sand soaks up the water and
maintains a reservoir to supply the plant.
Watering need only occur two or three times a week and the vines
can be
placed where they will have the required amount of light.
Many difficult species are now doing very
well.
A
few vines are completely deciduous and these pose special problems. The basalt soil has proven to be completely
unsuitable for some of these so they are also grown in pots. Instead of standing them in a tray, they sit
on a piece of black mulching plastic, or are grown in a hanging basket. The black plastic prevents the roots of
trees going up into the pots when the vines have died back. They are then not watered until the first
storms of early summer. This is the
only way we can grow Cynanchum leptolepis
and Ceropegia cumingiana.
The Zodiac Botanic
Garden is not open to the public.
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