Many people think they are limited in what they can grow because they don’t have a green house. As long as you are growing plants that are hardy to your gardening zone, your plants will be okay outside over the winter.
Plants in the ground rarely need to be covered for the winter. They will freeze, but that is okay. Their roots stay constantly moist in the ground soil.
Plants in pots dry out much faster than plants in the ground. Harsh winter winds speed up the drying process. Its a good idea to protect your potted plants from the wind to keep the roots from drying.
We used our hoop house to cover some small plants that we were propagating as softwood cuttings.
Hoop houses are a simple way to protect your potted plants from drying winter winds.
You can build a simple, durable hoop house out of concrete reinforcing mesh. You can find it at most home improvement stores, such as Lowes, Home Depot or Menards. It is used to strengthen concrete in sidewalks and driveways. They are sold in flats sheets or on rolls. Its best to get a roll so that it will already be bent into a round shape.
A hoop house frame made from concrete reinforcing mesh.
We’ve seen homemade hoop house designs made from PVC piping or livestock fencing. Concrete reinforcing mesh is heavy duty. It will last you many years and can stand up to a heavy snow fall.
Check out these pictures of a large metal hoop house that collapsed under a heavy snow fall. Concrete reinforcing mesh will not collapse.
We used 7 ft pieces of mesh and cut them to fit nicely over our propagation bed. Small bolt cutters worked really well for snipping the thick wires. When we made each cut, we cut through the middle of a square. The protruding wires made handy little stakes for securing each section into the ground.
Cutting through the middle of the square created stakes.
We cut our mesh into smaller pieces and are ready to place it over our propagation bed.
Leave an inch or two overlap for extra support
Our hoop house frame is in place.
Once your frame is in place, you hoop house is ready to be covered. This is very important:
Do not cover your plants until they have gone dormant!
Your plants need several hours of freezing temperatures to trigger them into dormancy. Dormancy is a period of rest for you plants. Like a bear in hibernation, your plants will sleep and slow their metabolism. This helps get them survive the cold, dry winter months.
Once your plants have gone dormant, cover your frame with 6mil WHITE plastic sheeting. White sheeting is sold in nursery supply stores. You are not likely to find it in at a hardware store. Most hardware stores carry clear or opaque sheeting. If you cannot find white sheeting then paint it white with latex paint.
It must be white. It must be white. It must be white.
White sheeting will reflect the suns rays. Clear, black or opaque sheeting will heat up your plants during the day. Your plants must stay dormant for the winter. You don’t want them heating up during the day and breaking dormancy. Then they have to fight to stay alive in freezing temperatures at night. Its too much stress on your plant. They must stay dormant.
The purpose of a hoop house is to block the drying winds, not to keep them warm. Hoop houses don’t have ventilation or heat. They do not create an artificial environment like a green house.
Give your plants a good watering before you put on the plastic.
Large hoop houses, like the ones found at most nurseries are designed to be opened and closed. They are large enough to allow tractors and workers inside. It hard to maintain humidity in all that open space and with workers coming and going so large hoop houses have irrigation lines installed so they can water the plants every 3 weeks or so….the irrigation lines have to be winterized…its a lot of work.
Short hoop houses have less dead air space and allow for more humidity. They are designed to be closed tightly all winter. If you give your plants a good watering before tucking them away for the winter, they should be fine until spring. If you are concerned that they might need more water, you can poke a small hole in the plastic and spray some water in with a hose.
Cover you hoop house in plastic sheeting. Notice our sheeting is not white?? We will paint it white with latex paint.
Cover your hoop house with one layer of white plastic sheeting. Pull it tight and make sure there are no gaps. Leave about 18 inches of plastic all the way around and weigh it down on all four edges with sand or soil. We prefer sand because soil is a muddy mess come spring.
Do not use bricks or lumber to hold your plastic in place. Trust me. Been there, done that, it doesn’t work! Wind will find its way in and tear your plastic.
Here is a helpful hint:
You can put large potted plants inside a small hoop house by placing them on their sides. Prop the first row up so they sit at a slightly diagonal angle. This will keep the soil from falling out of the pot. Prop your next row of plants up against the first.
A tip o.n FREE 20 mil white plastic sheeting. I get it all the time and it is super thick and free for the taking here in middle Tn. I go around to the local boat dealers (Big boats are best) and ask them to give me a call when they get some in. The boats are shrink wrapped with this great white plastic (have you seen them go by on the interstate?) and the dealer will cut it off and toss it in the dumpster so just take him a few plants and he will be glad to call you when a shipment comes in.
Great tip Robert!
Can this be done with raised garden beds?
Tim,
Sure, I don’t see why not.
Hi Mike,
How do I winterize my Dinner Plate Dahlia bulbs that I dug up? Also, can I separate the additional bulbs that grew on the original bulbs I planted. I live in Central Illinois.
Also, how do I tie the plants up so they don’t fall over? I used round green wires that has 3 prongs that go in the ground that I bought & it was not strong enough nor high enough to keep them from falling over. I figured I would have to buy at least 4 ft high bamboo posts to use, but there not very strong, so I’ll probably have to tie at least 3 to each plant. Am I correct? What can I use to tie them up with.?
Thank u for all your emails. They have helped. me a lot.
God Bless & Merry Christmas to u & your Family.
Tammie,
Dinner plate hibiscus over winter just fine in the ground. Dahlia I don’t know about. Use lightweight fence posts in you need that kind of support.
Good morning Mike,
I planted strawberries this spring in rain gutters. I have 4 rows that are 41′ in length. What is the best way to help them through the winter? I can not really put straw on them. I thought about bubble wrap them but read that need white plastic. Now thinking about getting white plastic and wrap them from top to under gutters to top again. .Is that the best way? I have soaker hose inside the gutter. Reading it says to water before covering them up as well. I would like to send a picture to you of what I have if that would help. But this part of paragraph would not let me copy and paste a picture.
Your help would be greatly appreciated.
Thanks,
Tony
Tony,
I really don’t know what would be best. All I can say is the closer to the ground they are the better. But I will say this, strawberries are pretty tough, pretty winter hardy, they might be okay uncovered but I can’t say that for sure.
Here in Virginia Beach, some of our commercial berry growers just leave them uncovered & they make it. Perhaps a little later, but still quite productive.
Hello, Mike, good article about the mesh hoop house. But a question in regard to dormancy. The article says “Your plants need several hours of freezing temperatures…”Living in north Florida I didn’t even see 32 degrees last winter. So when would I cover my plants under the hoop?
Claude,
Covering in your zone might not be a good idea. Around here we start uncovering as soon as the temps get up near 50 degrees F. Covering in your climate might do more harm than good. My question is what do growers around you do?
Hi Mike! I propagated 100 blue fescue this summer that are doing beautifully in a raised bed with 10″ of soil. But the bed is open below. (It looks like an old cattle feed trough.) Should I transplant the fescue into the ground before a hard freeze or cover them in the raised bed? Thanks so much! Love your posts which have helped bunches.
Marilyn,
I would prefer to see them in the ground. All that cold air beneath them is not a good idea. Not only will they be really cold, but they will dry easily as well.
Years ago, I built a reinforcement mesh mini-greenhouse. A small pair of bolt cutters are useful for cutting the mesh, and vise grips for bending and wrapping the cut ends where you want them.
Depending on how you cut the mesh, the ends may be razor sharp – so wearing gloves is a good idea.
The reinforcement mesh makes nice tomato cages, too.
AC,
You’re right about the bolt cutters and the jagged edges. You have to be careful when cutting that the loose end of the roll doesn’t come back and hit you in the back.
how wide is the bed you are covering? (how tall is the hoop house at center)
how big are the sqares in the concrete mesh (how much will be sticking in the ground….)
which will then tell us how wide is the plastic sheeting (exposed hoop + 18 + 18″ on sides)
if you use sand/soil to hold down the edges, what the heck do you do with it in spring? would “snake” sandbags work here? or roll the edges onto pvc and then sandbag those?
Hey Mike,
Any advice on digging the bed a foot below ground level to place pots? I’m digging out a 10×3 trench that I’ll either use lumber and rebar to frame and leave below ground to store pots for winter or fill with well draining soil.
I’ll use your mesh recommendation for the hoop house just asking how you do your beds?
This is important. In order to make recessed beds like I use for over wintering containers you ABSOLUTELY, POSITIVELY, MUST HAVE WELL DRAINED SOIL. I recess my beds anywhere from 8″ to 16″ below grade then shore up the sides with one by four material secured with EMT (electrical conduit). But if your soil cannot take large amounts of water and accept it quickly, sunken beds will not work. Very few people have the advantage of well drained soil like I do.