Canberra's 26th Floriade flower festival is open to visitors from this weekend.

More than a million bulbs are awaiting their admirers in Commonwealth Park next to Lake Burley Griffin.

This year's theme is Beautiful Innovation, with flower bed designs paying tribute to Canberra's icons and achievements in its centenary year.

The display features 161 plant varieties over the four hectare site.

Aside from the flowers, there will be hundreds of entertainment and events on offer, including cooking and gardening workshops.

Floriade's head gardener Andrew Forster says his team has put in a lot of hard work over many months.

"We've been tidying up all the edges, doing a final weed, just finishing things off," he said.

"It's always good to come to the first day when people come in and have a look around and just listen to what they have to say and it's really good, a really nice feeling when you get to that day."

Mr Forster says his team will be kept busy during the event.

"We start at six in the morning and do three hours before people get here. So we're blowing the paths, just tidying up bits and pieces, watering, and we'll de-head spent flowers as they finish," he said.

"Hopefully we'll get lots of people coming through the gates and having a good time."

Floriade Nightfest will also return for its sixth year and the ticketed event will run in the evening from September 25-29.

Last year's Floriade attracted 442,243 visitors, with more than a quarter of those people coming from interstate or overseas.

The crowds delivered a $27 million boost to the ACT economy, a figure the ACT Government hopes to expand on this year.

The free event will run for four weeks.

ACT Policing will randomly patrol the car parks during Floriade and are warning visitors to be vigilant about security.

Crime Prevention Station Sergeant Harry Hains says people should take a few precautions.

"Before leaving your parked car, it's important to take that extra minute to check that all valuables are hidden from view, the doors and boot are locked and secure, the windows are up and sunroof closed," he said.

"Leaving items such as wallets, mobile phones, sunglasses, money or CDs in plain view only serves as a temptation for petty thieves."

Police are also asking the public to report any suspicious behaviour around car parks during the event.