Farmers in North Queensland are doing their bit to be environmentally friendly by investing in a tree that produces diesel.

Over 20,000 trees have been sold to farmers in the tropics by the man who introduced the diesel tree from Brazil.

The tree produces an oil that can be extracted, filtered and used to power vehicles and farm machinery.

It is estimated a one-hectare crop could produce enough fuel for an average-sized family farm.

Mike Jubow, a former cane farmer and now a nursery wholesaler, says diesel-producing trees are a long-term investment.

"If I'm lucky enough to live that long enough - I'm 64 now - it is going to take about 15 to 20 years before they are big enough to harvest the oil so that I can use them in a vehicle," he said.

"Principally, they are an ideal plantation tree for a family farm where, from generation to generation, you will harvest this oil so that your grandson and your great-grandson can still be virtually getting free fuel from these trees 30 to 50 years in the future."

Mr Jubow says one hectare can produce around 12,000 litres of fuel per year.

"Last year we sold around about 20,000 of these trees. This year we'll sell probably similar figures, but we could sell more except that we can't get enough seed out of Brazil," he said.

He says the trees need a lot of water to grow.

"They have got to be in the higher rainfall areas like coastal Queensland, [which] is ideal from around about Rockhampton north," he said.

"They're early growth. They are known as a secondary successional tree, which means they will grow in the shade of other trees so it is wise to plant them as a mixed plantation with other faster-growing trees."

Mr Jubow says there has also been interest in the diesel trees from the Department of Primary Industries (DPI) in Queensland and Farm Forestry.

"Farm foresters are very interested in this tree. I do have some interest from the DPI in the Northern Territory and also Western Australia," he said.

"There is a world-wide database on plant species that have been known to become pests. This plant is not on that list."

He says farmers who want to grow the trees need to know what they are doing.

"It is a very difficult tree to grow from the point of view of a nurseryman like myself - it is not something where an amateur could just grab a handful of seeds and go and grow them," he said.

"It is not that simple. They are a very difficult seed to germinate."

If things go according to plan, it appears that the diesel trees could definitely be an asset to the environment.

"Here is a source of renewable energy," Mr Jubow said.

"Not only that, when the tree reaches its use-by date, you've got plantation-grown timber which is a very high-grade timber that is suitable for cabinet-making. It is a very ornamental timber.

"You are still keeping it out of the CO2 system by harvesting the timber and milling it and putting it into high-quality furniture."