For dahlia growing enthusiasts like Napier's John McCutcheon last week's great deluge of rain was a killer.

And the timing could not have been worse for many of the nearly 60 members of the Hawke's Bay Dahlia Circle as the damaging rains struck just 10 days out from the North Island National Dahlia Show - being staged at the Napier Tech Clubrooms off Whitmore Park this weekend.

"I had about 200 blooms before the deluge," Mr McCutcheon said. "Afterwards I filled a 240 litre wheelie bin with spent flowers - probably around 100 of them."

Several other Napier-based club members also had losses, although Hastings growers escaped major damage as the rains were not so heavy there.


"But that's the way it is and you can't do anything about it - although last year I had umbrellas up but this year I didn't."

However, while some locals may have lost a few flowers Mr McCutcheon said he still expected a good number of them to show off their finest alongside growers from all over the island who will be arriving for the show.

With about 40 different species of dahlia, large and small, cactus-type and ball-type, he said there would be plenty of diversity and colour.

He has been growing them for "many years" now and said they were a flower with a fascinating history which were not too difficult to grow but which needed "plenty of food".

He said history showed the Aztecs of South America grew them and ate them. Sugar could be extracted from some species while others have the right stuff to be able to make bread from. "And some of the tubers can be turned into a drink."

In terms of their own drinks, Mr McCutcheon said the show flowers would be picked and prepared on Friday morning and would effectively last through to Sunday without too much assistance - although the secret to watering them was to add a teaspoon of lemonade to a litre of water. "It's the sugar."

The show, which will be judged by members of the Dahlia Society of New Zealand, will be open to the public between 1pm and 4pm on Saturday and 9.30am and 3.30pm on Sunday. The North Island National event was last staged here in 2012. The show is the North Island part of the nationals.