Floriade appears to be a bigger moneyspinner for the ACT than originally thought but its pull as a tourist attraction is on the wane, prompting Tourism Minister Andrew Barr to warn that the flower festival must not be allowed to go stale.
Visitors to this year's Floriade spent close to $40 million - 30.1 per cent more than last year.
It had the second-highest attendance since turnstiles were introduced in 1999, with a tally of 448,987 people, including many making multiple visits.
A more accurate way of measuring the direct spend of Floriade visitors is being attributed to the bigger figures this year.
But the number of interstate and international visitors who come to Canberra specifically for Floriade has been steadily falling since 2010, as has their average length of stay in the national capital.
This year, 105,356 people visited Canberra specifically for Floriade - more than 25,000 fewer than in 2010 and some 17,000 fewer than last year.
They stayed an average of 2.4 nights, down from 3.1 nights in 2011 and 2.9 nights last year.
This flies in the face of a strategic five-year plan for Floriade commissioned in 2009 by the government, which outlined a key goal as encouraging visitors to stay beyond their average three nights. Instead, the reverse has occurred and visitors are staying for shorter periods.
Mr Barr said on Thursday if the downward trends continued he would be concerned.
He believed the centenary year, with its full calendar of events, might have had an impact on how long people stayed for Floriade, which is in its 26th year.
He said it was reasonable to expect that for some individual events the length of visits might have been shortened ''because people were coming multiple times [to Canberra], but if that trend were to continue beyond this year, then certainly it would need some attention.''
Mr Barr also defended Floriade's marketing strategy, saying the ACT was operating in a highly competitive tourism market against states with bigger budgets.
''It is challenging. Floriade is a mature event so people have a reasonable sense of what experiences they're going to get, and our challenge now is to provide a reason to come back every year or every second year,'' he said.
Yet the event remains a big moneyspinner for the Territory. Floriade 2013's increase in gross territory product was $58.5 million, which is the highest on record and an increase of 30.9 per cent on last years' $40.4 million.
''We've got a valuable commodity but we can't just sit back and just leave it as is and all will be well,'' Mr Barr said.
''It can go stale. It needs innovation and that's the challenge I've set the events team and I'm confident they are … looking at new ways to deliver the event.''
The government said the higher direct spend this year by visitors at Floriade was likely attributable to the introduction of more accurate measurements. Previously, visitors had been surveyed face-to-face on-site about how much they were spending, which made it difficult to estimate their total spend for the remainder of their trip.
This year, the consultant Repucom had been appointed through a tender process and used a post-event online survey to get a more accurate picture of how much people spent.
A total of 1130 people responded to the survey. The average daily spend was $180.
Of the total attendance, 415,375 related to Floriade day sessions and 33,612 related to ticketed NightFest events.
Mr Barr said the future of Floriade included having spin-off events in nearby areas such as West Basin, innovations in garden design and different events such as NightFest. Entry to the daytime events would remain free.
''The event has a fantastic base on which to build and successive governments have invested significant amount in the brand,'' he said.
''But it can't stand still. If it does, yes, there is a significant risk that it will go stale.''