What was once a huge plantation pine forest will be so again but this time careful planning, updated planting methods and the arrival of carbon offsets have made the stony hills of the Ingledene Forest, south of Tharwa, a valued commodity.

For now, it's a bleak and windswept landscape bordered on its one edge by the Murrumbidgee River corridor and with the Scabby Range to the west.

Charred and rotting pine stumps litter the landscape, serrated tussock and blackberries are rampant, regrowth pines have emerged in places and ever-resilient old gum trees, weathered and gnarled, are hanging on hoping for better times.

However, as senior forester Christian Bihlmaier points out this is not how it will look in 30 years.

Thousands of radiata pine seedlings are germinating now offsite ahead of a two-year program which will replant 490 hectares of forest, roughly equivalent to 500,000 trees.

Bulldozers will rip and prepare the poor, rocky soil over the coming summer in preparation for the first stage of the seedling planting in winter 2020.

"It will look a bit ugly for a while until the trees become established but once they gain hold, the pines grow about a metre per year," Mr Bihlmaier said.

"We will retain the older gum trees where we can and down through the gullies and water courses, create erosion controls and plant out with native hardwoods.

"There are also areas of cultural value here which are being identified and protected."

Small patches of remnant native woodlands will be retained but elsewhere the radiata plantations will be rolled out in a long-term program which the next generation of ACT foresters will see harvested around 2050.

It's also a market-driven approach by the ACT government which will generate 180,000 carbon dioxide equivalents, the common measure used.

In the recent budget the ACT government put $1.74 million over four years into the Ingledene forest program. Carbon abatement will return around $2 million so the program will more than pay for the reafforrestation and land management.

Then in 30 years the area would yield about 280,000 tonnes of renewable plantation timber worth considerably more than the $10 million it would fetch at current market rates.

Carbon sequestration using radiata pine is hardly new, but brings many advantages in areas of poor soil quality unsuited to agriculture or grazing.

The added bonus to the Ingledene program is that once established and resilient, the plantation would lend itself to recreational use such as mountain bike racing and possibly a rally track or two.

Environment Minister Mick Gentleman said the recreational potential of the area is a foremost attraction.

"There has been a huge take-up in mountain biking in the ACT and this project gives us scope to grow that," he said.

"There are areas of Kowen forest which are being assessed for future harvesting and that will restrict some of the mountain biking there. Ingledene creates that future riding and racing alternative."