Over Wintering and Season Extension of Organic Culinary Herbs in Unheated High Tunnels (FNE03-464)
The purpose of this project was to extend the season (on both ends) for organic herb production and find an economically sound method for successfully overwintering tender perennial herbs such as rosemary.  Through the use of a permanent 30’ X 96’ unheated greenhouse and a temporary moveable 12’ X 96’ unheated plastic covered hoop houses we were able to market fresh herbs from April – December.  The 30’ X 96’ unheated greenhouse with two layers of plastic and with additional hooped row covers was successful in overwintering tender perennial herbs including rosemary.  To our surprise we are also able to use the overwintered herb plants as mother plants from which we took cuttings for the production of potted herb plants.  We fully adopted the use of an unheated perennial greenhouse for increased herb production, higher quality, and longer production season. 

We acknowledge support from USDA NE-SARE for providing partial funding and support for this project

You can see our complete project summary here

Mint in the Unheated Perrenial Greenhouse


Purple Sage in the Unheated Perrenial Greenhouse


Rosemary in the Unheated Perrenial Greenhouse before winter


Rosemary in the Unheated Perrenial Greenhouse showing some damage and stunting


Rosemary in the Unheated Perrenial Greenhouse showing some
damage that can easily be trimmed back


Rosemary in the Unheated Perrenial Greenhouse with row cover-
Note snow outside- It is cold out there but protected in here!


Long view of the different herbs mid-summer in the unheated
Perrenial Greenhouse


View of the Perrenial Greenhouse in the Winter with Rowcovers


View of the Perrenial Greenhouse in the Winter


View of the Perrenial Greenhouse in the Spring

View of the Annual herb high tunnel in the summer


View of the greenhouses from our vegetable field
Propagation house, Perrenial Greenhouse, Annual Herb High Tunnel