Populations of a plant as rare as the critically endangered kakapo were discovered on a Wairarapa farm in 2013 and numbers are still growing strong.

The discovery more than tripled the known numbers of the Olearia gardneri and will hopefully lower its threat status from Threatened -- Nationally Critical, to Threatened -- Nationally Endangered, said Queen Elizabeth II National Trust's Wairarapa representative Trevor Thompson.

Mr Thompson stumbled across the plant Olearia gardneri, when he was assessing covenanting suitability on a Wainuioru working farm in 2013.

He said when he first met with farm owner Jane and her son Tom to see the area they wanted protected, there was "nothing very notable" about the property at first glance.


"However as we climbed down off a steep edge we came close to a small tree I recognised from past experience as Olearia gardneri, and then there was another and another and another," he said.

"And so it went on and some serious doubt crept into my mind, I must have this wrong, this is a very rare plant only known in very low numbers in widely scattered populations, I've made a mistake.

"But what Tom and I were looking at were the largest Olearia gardneri trees ever seen along with everything from young seedling plants and everything in between, an amazing find that had somehow gone unnoticed till then."

A comprehensive management plan has since been developed to enhance the current population, introduce plants to other tiny populations in Wairarapa, and set up new populations in other suitable covenanted sites.

Local Forest & Bird members are also helping out, clearing weeds from the site and collecting seeds and cuttings which have been passed on to Norfolk Road Native Nursery to grow for the plant's recovery programme.

Already 200 plants are ready for planting out in autumn.

Until this discovery, the total number of known plants in the wild was estimated at 160, but Mr Thompson counted 374 of them at the Wainuioru site.

A previous attempt by Masterton schools in 2010 to regenerate the plant in a programme unrelated to the National Trust on a different property in Wainuioru was unsuccessful.