...The tale of the Owens women begins in the 1600s...
The story dictated that the house had to be built on an island...
The location had an other-worldly quality to it and living on the island
proved to be an extraordinary experience for members of the production.
Completely unspoiled, the island and surrounding waters boast
a profusion of wildlife including bald eagles, seals, and Orcas.

Above text from the Practical Magic production notes

 

 

This cabin belonged to Maria Owens, built when she was first banished
to the island. Though the film is set in New England, the actual filming
was done in the San Juan Islands in Washington State.

While on vacation in Seattle in the summer of 1999, I visited the island
where Practical Magic was filmed. Among other things, I was told that the cabin
was constructed of new materials, and 'aged' to appear as it does in the film.
Moss was hand-applied to the roof, and the 'wood' was painted to show the years.