P.E.I.'s Hillsborough River Association has planted about 1,000 swamp milkweed plants in the hopes of preparing a home for monarch butterflies.

Glen Kelly

The habitat will be ready for the butterflies should they choose to come to it, says Glen Kelly. (CBC)

Prince Edward Island is at the extreme northern edge of the monarch's range, but the butterflies have been known to move into areas where milkweed, their primary food source, is plentiful.

Hillsborough River Association community liaison Glen Kelly hopes the plants will provide a sustainable habitat.

"Insect populations can crash and comeback successfully. They have got great propensity to increase their populations once the habitat is available," said Kelly.

Monarch Butterfly

Numbers of monarch butterflies have been declining it their southern breeding grounds. (Toby Talbot/Associated Press)

"If the things get fixed up down south where they over winter, we'll be ready. It may take years, but by having a large native population of these plants it will certainly help the survival of the species."

The monarch population has continued to decline significantly in recent years, mainly due to habitat loss in Mexico and other regions.

Kelly said his group will continue to monitor their numbers along the watershed.