Though she does spend hours each week tending to the plants in the iconic gardens so the opinion might be biased.

Ms Jones is one of the National Capital Authority's longest standing volunteer rose pruners.

The delicate task of tending to the plants and pruning the branches is left to a team of about 70 volunteers, who work year-round to ensure the roses, when in bloom, are at their best.

The volunteers look after more than 8000 rose bushes across the four gardens at Old Parliament House.

Ms Jones works with volunteer co-ordinator Ros Donohoe in the largest garden of the four, the Rex Hazlewood. In this garden alone, there are more than 1200 roses that need constant attention.

Both the Senate and the House of Representatives gardens hold two rose gardens each, situated behind the lush green hedges originally planted to keep politicians out of the public gaze.

The Senate rose gardens are known as the Rex Hazlewood the Broinowski.

On the opposite side of Old Parliament House, the House of Representatives garden hosts the Ladies and the Macarthur rose gardens.

When new Parliament House was built, the gardens were neglected for many years.

In 2004, all four gardens were resurrected, some with changes, but the Rex Hazlewood garden was reconstructed to the original layout.

The garden portrays the international history of rose cultivation, with eastern roses meeting western roses in the middle, where Australian roses grow.

All of the gardens have unique characteristics. In the Rex Hazlewood garden alone, there are more than 250 types of roses.

Ms Donohoe said the best thing about volunteering in the garden was being out in the open, connecting with new people.

"I enjoy making new friends, and I enjoy learning about the roses," she said.

"I'm not a horticultural extraordinaire, but I like learning and I particularly like the Rex Hazlewood garden because it's got the history of the wild rose, it's got the European and Asiatic roses, and it's got the very old varieties."

Each year in May, the volunteers hear about the latest pruning techniques in an effort to ensure the roses are being looked after in the best possible way.

Program co-ordinator Amanda Hynson said the refresher course taught the four Ds - dead heading, removing dead wood, recognising diseases and cutting on a slight diagonal.

"We have seen such improvements in the gardens in the quality of the flush each year, because of the techniques implemented in the gardens," Ms Hynson said.

"There's lots of things to consider, it's not as simple as coming in and cutting. You can't just go along with a hedge trimmer."

Ms Hynson said the volunteers were taught exactly what angle to cut at and where.

"When you look at how delicate some of these roses are, you can imagine how hard it is to get in there and get the exact right angle," she said.

While most of the pruning will happen over the next two months, the huge variety of roses mean there is work to do year round.

The team gave three top tips for pruning roses.

1. Hygiene - use a spray bottle with an equal mix of methylated spirits and water and spray the secateurs each time you move to a new area of the plant or a new plant.

"When you're using a secateurs on a plant, you've got to consider it's like an instrument in surgery so you're not contaminating [with disease] different sections of each different type of rose."

2. Prune carefully, with best practice. The key is to prune 5mm north of the bud, and cut at a very slight angle.

"It's unlike the old days when there was a deeper angle. It's just an ever so slight angle so you're not interfering with the growing and healing part of the stem," Ms Donohoe said.

3. Ensure the plant has sufficient welling to allow for a breeze to pass through.

"The welling is important, otherwise you get disease in the root and the branches and they die. Pruning is an opportunity to well your roses," said Ms Jones.