Several years ago, I began to experiment with year round gardening. I live in north, central North Carolina or zone 7B. It’s certainly not the coldest climate, but we have 4 distinct seasons with frost, ice, and the occasional snow in winter. A four season vegetable garden isn’t going to survive without a little help.
Most of my raised Lasagna-style garden beds are 4′ X 8′. This is the perfect size for mini hoop tunnels, but this type of cover could easily be used on a larger bed. From late fall to early spring, I use them to protect spinach, kale, lettuces, leeks, broccoli, and other greens from freezing temperatures. I can enjoy fresh vegetables when most gardeners have closed up shop. Even the old timers in my area are surprised by what I can grow with the mini greenhouse tunnels.
Here are the supplies you need for a mini hoop green house tunnel.
Fits a 4’x8′ raised bed. The supplies can be purchased at most large hardware stores or on line.
- The Frame – (5) 1/2 inch PVC pipes
- The Support – (10) 12 inch rebar
- The Cover – 4 to 6 mil poly plastic and fabric covers
- Plastic snap clamps – 10
Mini hoop tunnels are easy to put up and take down and extremely inexpensive to build.
Step 1: Rebar
The hoops are secured by 12 inch rebar pounded into the ground about 6 inches. Place 5 down each side evenly spaced starting at the end of the bed and finishing at the other end.
Step 2: The Frame – PVC pipe
I purchased 1/2 inch PVC pipes because they’re sturdy and flexible. I use 5 for a 4′ x 8′ garden bed placing them about 1 1/2 feet apart. You may need more or less depending on the size of your garden bed. I like them close together, but 3 feet apart should be the maximum. Insert the ends of each PVC pipe onto the exposed rebar.
Step 3: Cover materials
I use several different types of covers through out the year. In late fall and winter, I use heavy clear plastic 4-6 mil thick purchased on a roll I cut to fit each bed. The cover needs to be at least 10 feet wide by 20 feet long. This will completely cover the bed with a little extra.
During the spring and summer, I use a light to medium cloth cover purchased online to protect seedlings from cool temperatures and insects.
Step 4 : The plastic snap clamps
Use the snap clamps to secure the plastic cover to the PVC pipes. I place 1 clamp at the base of each pipe to hold the plastic tight. If you live in a windy area, place 1 at the top of each arch.
Four Important Rules for Using a Mini Hoop Tunnel
- Ventilate. If the weather warms (50 degrees Fahrenheit or higher), you must open the ends of your tunnels or lift the sides to allow air to circulate and prevent the temperature inside from getting too hot.
- No Contact. In the winter, if your plants touch the plastic cover they will freeze. Make sure the frame and cover allow for plenty of room.
- Secure well. Make sure that the rebar, hoops, and cover are secured well to prevent a winter storm from blowing off the cover. This could damage your crop.
- Weather App. Check the temperature and weather conditions so you don’t wake up to an unfortunate surprise.
You can also insure success by adding organic matter like compost to the garden before planting. Then top it off with an insulating layer of mulch, such as shredded leaves or straw. Water during sunny days while the temperatures are mild. Once the temperatures stay below 40 degrees Fahrenheit day and night, the cover needs to stay on and you won’t need to water.
In extreme temperatures, you can add an extra layer of protection by covering the tunnel with a blanket. If it snows gently sweep off the snow when it gets too heavy.
I’ve created a garden planner PDF with the information you need to easily create your own delicious year round garden. My free planner includes finding your planting zone, first and last frost dates for your specific location, a seed planting time table for over 30 vegetables and herbs, and a garden planner you can print.
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