A vast Brisbane rose garden is still blooming after 100 years, but how did it withstand the Sunshine State's floods, humidity and extreme heat?

New Farm Park's rose garden, located in one of the city's most popular suburbs, holds 2,500 roses of different varieties and colours.

Established 1914, the heritage-listed park started with 800 roses planted in 1916, and by 1940 the state's tourism bureau reported that rose numbers had swelled to 20,000.

Paul Hains believes the New Farm Park rose gardens are some of the best in the country. ( ABC Radio Brisbane: Jessica Hinchliffe )

Queensland Rose Society president and Australian Rose Society vice-president Paul Hains said over the years the park housed some of the country's finest flowers.

"The rose garden has been here for a long time and has survived floods, droughts and rain.

"It was once a much larger garden then, but now there's still thousands of roses and in international terms it's considered a major rose garden."

Among the varieties are classics such as Iceberg, Playboy, Peace and Mister Lincoln roses.

The varieties are marked throughout the gardens and many are trialled by the Queensland Rose Society before planting.

The Double Delight roses have been a constant breed in the garden for decades. ( ABC Radio Brisbane: Jessica Hinchliffe )

Mr Hains said the garden held roses from across different decades and tastes.

"One of the well-known roses in the garden is the Double Delights; many traditionalists like the roses that have a perfect centre," he said.

"Many people think that means that it's a real rose, but the reality is that there's hybrids from crosspollination to create something different."

Mr Hains, who also breeds roses, said the trials helped select the right varieties for the different areas of the park.

Miss P Conrad and Miss C McGuire in the rose garden in New Farm Park in 1954. ( Flickr: State Library of Queensland )

"You have to test them so you know if it will grow in a different climate, how the rose will grow in two or three years' time, and how does the rose establish itself."

The history that shaped the roses

In the 1940s Harry Oakman was the head gardener for New Farm Park and redesigned the flower beds, organising them into variety and colour so the public could be educated about the gardens.

Parts of the 1940s spiral design rose garden still remains near the bandstand.

An aerial view of New Farm Park and the large rose gardens in 1937. ( Flickr: State Library of Queensland )

The number of roses increased in the 1960s and 1970s, and The Telegraph, Brisbane's evening newspaper at the time, claimed there were 40,000 roses in the park in 1965.

The infamous 1974 floods covered the rose beds with silt and many of the original plants were lost.

The rose garden continued to evolve over the decades to include climbing roses that line the arbour that wraps around the gardens.

"The Iceberg roses that are here have needed more care over the years, but there are many roses here that require little care," Mr Hains said.

"If you pick the right roses in Queensland they can do their own thing and that has been proven over the years."

The rose gardens are key for bees and other plants in New Farm Park. ( ABC Radio Brisbane: Jessica Hinchliffe )

When spring has sprung

He said spring allowed many of the older rose plants to flower.

"It's the time of year for growth here in the garden, so there are many plants in bud and new ones that are in.

"The flowers will bloom through till June but the older roses will only be flowering now."

He added that the warm and humid temperatures worked for roses when treated correctly.

"Roses are not native to the Southern Hemisphere; we're still breeding with European and Asian plants but the Australian roses are bred now for the area."

Some of the original rose gardens are still in place on the flat area of the park. ( ABC Radio Brisbane: Jessica Hinchliffe )

Seduction grows well in Queensland

In the 2000s a lack of rain caused damage to many of the roses.

Since then, more trials have been conducted on each of the varieties used.

Mr Hains said most roses were tested for a number of years to ensure they were pest and disease-resistant.

"We recommend what grows well where in the state and which roses can withstand the heat."

The different varieties of rose include creeping roses, hybrid teas and bushes. ( ABC Radio Brisbane: Jessica Hinchliffe )

As a breeder, Mr Hains said the first thing he did when breeding new roses was ensure the perfume was strong.

"I start propagating in February, then plant the cutting in March or April and then by May I have flowers.

"Within seven or eight months you have a flower to look at and that gives and indication of what it will become."

He suggested that home growers should experiment with a variety of roses, drawing inspiration from New Farm Park.

"The Seduction variety grow really well here in Queensland, hybrid tea and a white Pope John Paul II do very well as well as the red City of Newcastle.

"Water them every week and fertilise them three times a year, and if you did that alone you would grow good roses."

Brisbane City Council hopes to boost the number of roses in the park to 5,000 in the near future.