The Netherlands, the world's top flower exporter, sold 3.6 billion flower bulbs abroad in 2010 - a two percent rise on the year before, the Central Statistics Bureau said on Monday.
But while sales volumes increased, the value of the flowers sold dropped by six percent to 313 billion euros ($ 444 billion), it said in a statement.
"This is probably due to the exchange rate," which favoured the American dollar, CBS spokeswoman Senne Janssen told AFP.
Two out of every 10 bulbs sold went to the United States, which remained the biggest single market despite a 10 percent drop in sales from 2009.
Sixty percent were destined for countries in Europe.
Half of all bulbs exported were tulips, followed by gladioli, narcissuses and hyacinths, said the CBS.
In 2010, 23,200 hectares of Dutch agricultural soil were reserved for flower and bulb cultivation, compared to 23,500 hectares a year earlier. There were about 1,700 flower growers, a drop of seven percent.
In 1980, the Netherlands had about 4,916 flower growers.
Bettina Wulff, wife of the German president Christian Wulff, will open the 62nd annual flower show at Keukenhof, the world's largest bulb garden, near Amsterdam on Wednesday.