A hoop tunnel can create instant shade to protect leafy greens and other cool-season vegetables from intense summer sun.
Cover half hoops made of PVC pipe, stiff wire, or construction- or chicken-wire with shadecloth or light horticultural cloth to keep leafy crops from sun-burning.
For tall crops such as tomatoes simply drape muslin, cheesecloth, or light row cover material over plants for temporary shade.
How to Make a Hoop Tunnel:
• To construct a 5 foot long shade tunnel, you will need three 4-foot sections of 1-inch diameter flexible PVC pipe and six 10-inch metal stakes narrow enough to fit into the ends of the pipes.
• Put the stakes into the ends of the pipe and then arch the flexible pipe over the bed and drive the stakes into the ground or create hoops.
• Cover the half-hoops with shadecloth or horticultural fabric.
• You can secure the fabric in place with garden staples, soil, boards, or stones on the ground or with clothespins attached to the pipe.
• Hoops can also support floating row covers to keep insects out of vegetable beds, sheet plastic to protect from early frosts or to warm the beds in spring, or netting to keep birds from eating your crops.
• Construction wire, chicken wire, and fence-wire also can be used to make row- or bed-wide tunnels. Arch the wire over the row or bed, secure the wire with stakes, and cover with shadecloth or floating row cover cloth.
• Shade tunnels can also be fashioned by bending stiff wire into loops, pushing the wire into the soil 1 to 2 feet and stretching shadecloth or horticultural cloth over the hoops.
For seed beds and seedlings you can make temporary hoop tunnels using wire coat hangers.
Dark shadecloth material which can hold heat should be attached to hoops well above plants to allow air to move over the plants easily. White shadecloth can lay closer to plant foliage—even directly on them—because it reflects heat.
Shade is essential for most vegetables once temperatures climb above 100°F. Shade will protect foliage and fruit from sunburn and stress. Watering can help cool plants, but when there is a prolonged heat wave watering every day can run the risk of drowning plant roots.
More tips: Watering Vegetables in Hot Dry Weather.