Last-minute Mother's Day gift givers stocking up on cards, chocolates and flowers for mum make the second Sunday in May a busy one.

Countdown supermarket said they usually sold eight times as many flowers on Mother's Day than the average Sunday, according to sales data.

Last year the supermarket chain sold 50,000 Mother's Day cards around the country - three times as many cards sold on Valentines Day.

And those buying a bouquet for mum went for more expensive bunches, spending on average $3.50 more on Mum than they did on a bunch of flowers for their valentine.

Over half of the flowers sold on Mother's Day were bought between 9am and 1pm, and 131 customers made a last-minute dash to buy their Mum's flowers after 8pm on Sunday night.

More than 150 Johnny-come-latelies snapped up a card for mum the Monday after the big day.

Countdown was four times more likely to sell boxed chocolates on Mother's Day than on the average Sunday, with mums most likely to be treated to a box of Cadbury Favourites, Lindt Lindor Bags, Cadbury Roses or Scorched Almonds.

Countdown's general merchandise manager Scott Davidson said there was no need to panic if you'd forgotten Mother's Day tomorrow with supermarkets open until 10pm tonight, and in some cases open 24 hours.