Coconut development minister Jagath Pushpakumara said the government had outlawed the cutting down of coconut trees in a bid to maintain local production that has been falling steadily in recent years.
"With immediate effect, we have banned the felling of coconut trees," the minister said.
The coconut is so important to national cuisine that shortages in the past have had serious political implications and have even been blamed for the downfall of governments.
Last week, the government set a ceiling retail price of 30 rupees (27 US cents) per coconut in a network of state-owned stores, but stocks quickly sold out and then reappeared at more than double the price on the black market.
The trade ministry has already placed orders to import coconuts from India.
Coconuts have traditionally been a key Sri Lankan export, after tea and rubber, but the conversion of plantations for housing development and increased consumption has led to severe shortages.