Harris Seeds Row Cover

The slits are designed to open slightly when the air inside warms up, allowing excess heat to escape during the day. As temperatures drop in the evening, the material naturally settles back into a sealed position to trap warmth and protect against frost.

Yes, wire tunnel supports or plant hoops are highly recommended. Because this is a lightweight polyethylene film, it needs a structure to hold it above the plants, preventing the plastic from crushing delicate foliage while creating the necessary air pocket for heat retention.

This cover is effective for light frost protection, typically down to 1-4°F. It is best used for extending your season in early spring or late autumn rather than surviving deep, prolonged winter freezes.

No, this polyethylene cover is not water-permeable. You will need to remove or lift the cover periodically to water your crops, or ensure your irrigation system is set up underneath the hoops before installation.

Under sunny conditions, you can expect daytime temperatures under the cover to be 10-30°F warmer than the ambient air temperature. This boost is what accelerates crop maturity and allows for earlier planting.

While the 0.8 mil thickness is durable, it is not puncture-resistant or UV-stabilized for long-term permanent exposure. With careful handling during installation and removal, you may get more than one season out of it, but it is not designed to be a permanent landscape fixture.