This from the Allendale Facebook page (their all-capital letters, not mine):
"THE COUNTY OF BERGEN IS SCHEDULED TO CLOSE FRANKLIN TURNPIKE TO ALL TRAFFIC FROM ALLENDALE AVENUE TO COTTAGE PLACE STARTING ON OR ABOUT WEDNESDAY, SEPTEMBER 3RD TO REPLACE A BRIDGE AT THE INTERSECTION OF ELM STREET AND FRANKLIN TURNPIKE.
THE CLOSURE IS EXPECTED TO LAST SIX MONTHS.
ACCESS TO ALL BUSINESSES SHALL REMAIN DURING THIS PERIOD. HOWEVER, YOU ARE URGED TO SEEK OTHER ROUTES DURING THIS CONTRUCTION PROJECT TO AVOID DELAYS."
You can still get to the Celery Farm via Allendale Ave. to Cottage Place, but it's tough to predict how bad the traffic will be.