AMSTERDAM (Reuters) - A 73-year-old Dutch man was astonished to learn from police that the begonias he had lovingly tended on his doorstep concealed a secret marijuana plantation.

"Police officers suddenly noticed marijuana plants sprouting from his begonias," a police spokeswoman in The Hague said on Friday.

The Hague pensioner promised to destroy the marijuana plants, which he believes were planted by local youngsters, while preserving his begonias.

Earlier this month the Dutch government set up a task force to crack down on marijuana cultivation in the country.

Growing marijuana is illegal in the Netherlands, but sales of it and other cannabis-related soft drugs in coffee shops have been tolerated for decades.

(Reporting by Alexandra Hudson)