The following comes from Tom Schipper with Colorblends, Inc, a bulb purveyor located in New England.
Other than the drop in outdoor temperatures, Schippers recently asked his customers to
share their own “natural guidelines.” Here are a few customer comments for knowing when it’s time to plant bulbs:

• Fall foliage has moved just past peak
• Crickets no longer chirp
• Squirrels are digging in acorns as fast as they can
• Birds start to group and depart
• You start turning on the heat in your car
• The air smells of wood smoke
• Grapes are ripening on the vine
• You blow out the irrigation system before the winter freeze
• The hostas start to lie down
• The air has that organic, decaying leaf smell
• The dog moves from a cool to a sunny spot in the yard
• The kids start putting on their jackets without being nagged by you