Organizers of the annual garden marathon have extended the course cutoff from seven days to nine, citing a run of dry autumns that left many entrants stranded on the gravel path.

The course, which runs once around the outer edge of the garden, has not changed in years. But the weather has, organizers said, and the old cutoff no longer reflected how long the course takes in a dry season.

Most entrants welcomed the change. A few veterans grumbled that the new limit was too generous. “In my day we finished in six,” one said. “Of course, in my day it rained.”