Considerations with high tunnels/greenhouses prior to a hurricane
Check the area around the structures for loose objects. Look for objects that could be blown at the structure and cause damage to the glazing and remove them.
Inspect for dry or weak tree limbs that could fall on the greenhouse.
In general, you should close all vents to minimize the ability of the wind to lift the structure.
Consider removing the plastic if anticipated wind speed will reach greater that 80mph (this threshold could be higher or lower depending on the rating of the specific structure).
On air inflated greenhouses, increase the inflation level between the two layers of plastic covering. Also, tape and repair any tears/rips in the covering.
If the structure is equipped with a heater, secure the exhaust pipe as it can move easily in high wind.
Remember to vent the structure after the storm has passed if crops are inside.