She said it had been busy leading up to the day, estimating she had between 100 and 150 Valentine's orders so far, mostly for red Prestige roses.
"That's not taking into account people walking in off the street."
Mrs Cullen said the single red rose, the traditional symbol of love, priced at $14, was a popular option. "It's quite good value."
People were also buying six roses, at $75; the classic dozen, $145; and $65 Valentine-themed romantic bouquets.
She said it was one of the busiest days of the year, particularly when it fell on a weekday. "Valentine's Day is bigger on weekdays because people can send them to workplaces and schools."
It was also particularly busy because it was currently wedding season.
"This year it has been massive."
Masterton's Esaus Florist owner Linda Neal said she had been flat out and was planning to be at work by 5am today.
"It's a full-on day, the key thing is to be really organised."
There was always a last-minute rush, said Mrs Neal.
"One year, I had a guy knocking at the door at seven in the morning.
"People think, 'Oh my God it's Valentine's."
She said she wasn't sure how many orders she'd had so far as she was too busy to count.
"We are nearly out of the six long-stem rose bunches. If someone wanted 12, they'd probably be out of luck."
Mrs Neal, who gets her roses from Moffat's Flowers in Christchurch, said she'd had a lot of teens ordering flowers this year and seen a change in the clientele.
"There are more men this year. In the past, there's been more women than men."
For people who haven't made it in time to get a loved one roses, they could always send digital ones, which are a lot cheaper than the real thing.
People can buy an app for a $1.29 to send a 3D rose that plays romantic music and allows the receiver to download a free high-definition wallpaper of the rose.
There are more than 100 mobile phone apps on Android and iPhone, some of which are free, that can be used to send virtual red roses.