The horticulture industry is worried some plant species will disappear for good as more nurseries close.
Plant nurseries, particularly those close to big cities, are shutting down as property prices soar and land values go up.
In West Auckland alone, two nurseries - both of which have been around for decades - are set to shut this year.
The publisher of the nursery industry magazine, Des Snell, said people often just wanted to retire and there was no one to take over the business.
He said as land values rose it could be easier to sell to developers.
"The overall result is that a narrowing all the time of the plants that are available in New Zealand.
"And that's a worry for a lot of people, you know, in the trade.
"If it continues for many years there'll be a big dumbing-down of plant life in New Zealand."
Mr Snell said it would be a tragedy to lose plant species grown in the independant nurseries.