- Bobcat Standard High Tunnel Kit (#6795) | Parts List (PDF)
- Video: Planning & Planting the Autumn Vegetable Garden | Tips & Recommendations with Niki Jabbour
- Winter Growing Guide | Protection Methods for Overwintering in Low Tunnels
- Protect Your Crops | High & Low Tunnel Basics
- Bobcat Basic High Tunnel Kit Manual (#6923) | Tech Sheet (PDF)
- Winter Production in the High Tunnel | Johnny's Winter Growing Guide
- Beginning & Intermediate Controlled Environment Agriculture (CEA) | Advances in Greenhouse Crop Production
- Bobcat Basic High Tunnel Kit (#6923) | Parts List (PDF)
- Hitch Mount for QuickHoops Low Tunnel Benders | Instruction Manual (PDF)
- Be First & Last to Market by Extending Your Growing Season
- QuickHoops Gothic High Tunnel Bender | Construction Manual for Stationary Gothic High Tunnel (PDF)
- Univent Automatic Opener for BiFold Doors | Instruction Manual (PDF)
- 10 Ways to Extend Your Season with Protected Cultivation
- Hoop Loops | Installation Instructions | Tech Sheet (PDF)
- Winter Growing Guide | Scheduling Guidelines for Overwintered Crops
- Bobcat Sliding Door Kit Manual (#6792) | Tech Sheet (PDF)
- Bobcat Pro High Tunnel Kit (#6794) | Parts List (PDF)
- Quick Hoops Low Tunnels | Set-up & Management with Eliot Coleman
- Moving the Modular Moveable Gothic Tunnel – Slideshow
- Growing Under Cover with Niki Jabbour & Johnny's | Johnny's Educational Webinar Resources
- Winter Growing | Recommended Crops & Varieties
- Video: Johnny's Season Extension & Overwintering Trials
- Recommended Varieties from Our Greenhouse Trials | What We Look For in Greenhouse Crops
- QuickHoops Seedling & Microgreens Bench | Construction Guide (PDF)
- Agribon+ AG-19, 30, 50 & 70 Row Cover | Insert (PDF)
- QuickHoops 3'W x 4.5'H Low Tunnel Bender (#7616) | Instruction Manual (PDF)
- Johnny's Winter Growing Guide | Printable 10-pp Brochure (PDF)
- Bobcat Pro High Tunnel Kit Manual (#6794) | Tech Sheet (PDF)
- Bobcat Automatic Ventilation Kit Manual (#6791) | Tech Sheet (PDF)
- QuickHoops Moveable High Tunnel Bender | Instruction Manual (PDF)
- Row Cover & Insect Netting Options & Uses | Comparison Chart (PDF)
- Why Grow in a Greenhouse? Basics & Advantages of Protected Culture
- Video: Take a Tour with Us of Johnny's Greenhouses!
- Planning for Opening Day at the Farmers' Market or for Wholesale Accounts
- Winter-Harvest Crops | Planting Chart for a Seamless Winter Harvest
- Winter Growing Guide | Introduction & Part 1: Scheduling Your Winter-Harvest High Tunnel
- Bobcat Tunnel Kits | Comparison Chart
- Video: The Benefits of Row Covers | Recommendations & Tips from Johnny's Selected Seeds
- Video: Hoop Houses & Other Ways to Extend Your Growing Season
- Cable Purlin Trellis for QuickHoops High Tunnels | Installation Manual (PDF)
- Skinning the Modular Moveable Gothic High Tunnel – Slideshow
- QuickHoops Low Tunnel Benders | Instruction Manual (#9377 & #9520) | (PDF)
- Video: How to Use Quick Hoops™ Benders to Create High & Low Tunnels
- The Effect of Shorter Daylength on Winter Production
- Video: Growing Under Cover with Niki Jabbour | Johnny's Webinar Series
- Constructing the Modular Moveable Gothic Tunnel – Animated Schematic
- QuickHoops High Tunnel Bender | Construction Manual for Building a Stationary High Tunnel (PDF)
- Overwintering Onions from Seed | Johnny's Selected Seeds
- Overwintering Crops | Planting Chart for Earliest Spring Vegetable Harvest
- Video: DIY Cold Frame • Easy How-to Tutorial with Niki Jabbour
- Truss Support Kit Manual (#6790) | Tech Sheet (PDF)
- Bobcat Standard High Tunnel Kit Manual (#6795) | Tech Sheet (PDF)
- Video: Cover Cropping for Field & Garden with Collin Thompson | Johnny's Webinar Series
- Pest & Disease Control Basics in Greenhouse, Hydroponic & Other Protected-Culture Systems
- QuickHoops Elliptical High Tunnel Bender | Construction Manual for 24'-Wide High Tunnel of Any Desired Length (PDF)
- QuickHoops Gothic High Tunnel Bender | Construction Manual for Modular Moveable Gothic High Tunnel (PDF)
- Tufflite IV Greenhouse Film | Comparison Chart (PDF)
- Bobcat Steel End Wall Kit Manual (#6793) | Tech Sheet (PDF)
- Pests & Diseases of Greenhouses & Hydroponic Systems | Tech Sheet (PDF)
High Tunnels, Low Tunnels, Row Covers & Mulches
Protected cropping is the single biggest trend in horticulture today. High tunnels, low tunnels, row covers, and mulches can be used to protect crops from bad weather. Protected cropping can extend the season for months, while increasing yields and improving quality of vegetables, fruits, herbs, and flowers.
High Tunnels / Hoophouses
The ultimate tool in protected cropping is a high tunnel (also called a hoophouse), which is an inexpensive, unheated greenhouse erected right in the field. Hoophouses are quickly becoming an essential component of most produce and flower farms. A single layer of greenhouse poly over metal or PVC hoops, tall enough to walk into, provides an amazingly different growing environment. Hoophouses don't need electricity or heating systems, although some growers do add them to extend the season even further. In general, though, roll-up or roll-down sides are used to ventilate a hoophouse, and the sun does the work of heating it. Johnny's offers a line of professional-grade high tunnel kits to make construction more straightforward for DIY'ers.
Some of the crops that are commonly grown in a hoophouse include lettuce and greens, early and late in the year; strawberries in spring; raspberries and tomatoes in summer; and spinach and other cold-hardy vegetables over the winter. Many other crops will benefit from the protection, depending on regional variations. With careful crop selection, a hoophouse can be the most productive land on a farm.
Another protected cropping tool is a low tunnel. Low tunnels are made of small metal or PVC hoops, pushed into the soil over a bed of crops, and covered with spun-bonded polypropylene row covers. We've found that hoops fashioned from EMT (electrical metal conduit) are much sturdier and longer-lasting than those made of other materials, and thus more economical across time.
Low tunnels warm the soil and protect plants from frost and wind. They can be used early in spring for cool-weather crops, in late spring to give a head start to warm-weather crops such as tomatoes and peppers, and again in fall to keep cool-weather vegetables growing longer. They also are useful for protecting crops from predictable insect pests such as flea beetles and cabbage moths.
Using a low tunnel within a high tunnel is useful in cold climates to keep the soil from freezing until the dead of winter. Although plants stop growing when the days are short in mid-winter at higher latitudes, cold-hardy vegetables such as carrots and spinach can be harvested nearly all winter in this system.
Row cover alone can be pulled over crops to save them from untimely frosts. Late and early frosts are often one-night affairs; protecting against those relativel short-lived dips in temperatures can keep crops alive for several additional weeks of good growing conditions. Most growers keep a supply of row cover on hand for just such emergencies.
Plastic or paper mulches are another component of protected cropping systems. Black solar mulch warms cold soil; white-on-black mulch keeps soil cool. Biodegradable and paper mulches eliminate the need to take them up at season's end. All types suppress weeds, reducing labor.
By employing some or all of these protected cropping systems, growers can take some of the risk out of farming and gardening.
For more ideas about hoophouse production, browse our extensive Season Extension Library.
Lynn Byczinski's book, The Hoophouse Handbook, is another one of our favorite resources.
Byczynski and her family have been growing vegetables and cut flowers since 1988, selling through CSAs, at farmers' markets, to chefs, grocery stores, and florists. They currently grow cut flowers and hoophouse tomatoes on about 2 acres of their 20-acre farm near Lawrence, Kansas.
She is also the author/editor of two of our favorite books about market farming, The Flower Farmer and The Hoophouse Handbook.