I’m often asked for winter gardening tips or how to get started with a cold season garden.
It depends on where you’re located, what you like eating, and when you want to harvest your produce. However, I’ll provide some fall and winter gardening tips that will be helpful for you no matter where you live.
Warning: once you’ve tried gardening during the cold months when the bugs and diseases are dormant, you may find you enjoy your fall/winter garden even more than your summer garden!
Using Low Tunnels, aka “Polytunnels”
In South Carolina, low tunnels (also called polytunnels) are my preferred method to grow in the late fall and winter. Our weather is warm enough that I usually don’t have to start covering my plants until early December.
It’s also possible to grow through the winter in colder regions, but you may need additional protection. Two great learning resource you might want to consider:
- The book Four Season Harvest by Eliot Coleman, who grows year-round in Maine (yes, Maine!).
- A nice collection of zone-specific growing tips collected from readers of Mother Earth News.
Assembling Low Tunnels
Fortunately, low tunnels are extremely simple to put up and break down.
All you need are:
- Hoops – You need metal or plastic hoops that will stand at least a few inches higher than your tallest plants.
- Cover – Plastic greenhouse film or row cover to stretch over the hoop frame.
- Weights – Weights such as sandbags, rocks, or logs are useful to keep out drafts and hold the plastic in place where it meets the ground.
Low Tunnel Dimensions
My rows are 2′ across x 8-10′ long. I space our hoops 2′-3′ apart down the row with 1 at each end, so each 100′ roll yields enough hoops to cover 5-6 beds.
Where to Get Low Tunnel Materials (Hoops, Cover, Weights)
Hoops can be made from any 6′ – 8′ bendable material such as half-inch PVC pipe or concrete wire ladders. After years of trying out many options, I purchased galvanized metal hoops that will last indefinitely.
If you don’t need too many, here are really good metal hoops you can get that are quite tall.
However, if you’re like all of us on the GrowJourney team and you grow many, many rows of winter veggies, you may want to go with something more economical. We’ve found that 9 gauge, single strand, galvanized wire works perfectly and usually costs ~$10/100 ft.
2. GREENHOUSE FILM OR ROW COVER
I use this greenhouse film that only needs to be replaced approximately every four years.
Aaron (GrowJourney’s cofounder) has recently started using this 0.5 oz fabric row cover and prefers it versus greenhouse film since it’s more breathable and doesn’t have to be removed as often as greenhouse film.
If you live in a colder climate zone than 7B where we live, you may want to consider getting a heavier 1.5 oz row cover.
For the typical home gardener, there’s no reason to buy sandbags or weights to hold your cover down. Instead, gather rocks, logs, or other heavy objects you already own that can serve this function for you.
Temperatures: When to Use Low Tunnels
It’s important to be aware that the covers are not just to protect your plants from freezes. Most cold season crops will survive in the low 30º Fs, but they won’t continue to grow at those temperatures.
- BELOW 50º F – If you want vigorously growing plants and ample harvests, you’ll want to cover your plants when temperatures drop below 50º F.
- ABOVE 50º F – Conversely, when temps rise above 50º F, remove the covers so your veggies don’t bake before you get them into the kitchen.
Wireless outdoor thermometers that record last night’s temps are a great way to keep up with how cold or cozy your garden is.
For a home garden where you’ll typically only have a few rows to cover, use rocks, bricks, logs, or something similar to hold the cover down on your hoops. There’s no reason to spend money on sandbags.
Preparing Your Fall & Winter Garden Bed (Or Beds)
Once you have your hoops and cover, you’ll need to prepare a bed. As mentioned earlier, I use beds that are about 2′ wide and around 8′ – 10′ long because it works well with the tunnel shape.
For wider beds, use longer hoops so the arches stay well above the plant leaves. On cold nights, plants will get frostbite directly where they are touching the plastic. Interestingly, fabric row cover doesn’t seem to cause the same freeze problems when the leaves underneath touch it on a freezing cold night.
Your success is directly connected to your soil conditions. In fact, good soil is the most important element for a gardener to focus on. Organic amendments like compost and a weed and moisture barrier mulch will do wonders for your soil.
If you’re direct-seeding your beds, you should use a lightweight mulch like wheat straw (not too thickly) or even a layer of compost, so the young seedlings can push through the surface as they germinate.
However, when putting in transplants you can mulch around them with leaves, wood chips, or other heavier organic matter as long as the mulch isn’t piled up against the base of the plant. We like to pile mulch up in the paths between the rows as shown in the picture above.
When and What to Plant
What you are growing and when you want to harvest it are directly related to each other. The best way to find out growing requirements is to look up the individual plant you are interested in to get more targeted information.
If you’re a GrowJourney member, our GrowGuides and Quick Guides are an excellent place to start (some growing info, such as “days to maturity” is also on the GrowJourney seed packets).
Your local Cooperative Extension Service will have the most accurate information for your specific region regarding planting dates, but you may need to call and ask to speak to an extension agent so that you can mention you are using low tunnels.
The planting date charts on extension websites are usually for unprotected crops, not crops grown under row cover.
It’s easy enough to find lists of cold season plants online, but most do not specify how to get these plants going in a fall or winter garden.
Some plants work best sown in late summer so they will ripen with the first frost (broccoli, cauliflower, heading cabbages), some can be started in the winter so that they will ripen in the early spring (peas, fava beans, French sorrel, podding radishes, mâche), and some are flexible enough to produce all winter long (most greens, small radishes, carrots, turnips).
A few plants need a long fall – spring season to completely ripen (garlic, Brussels sprouts, parsnips, daikon radishes). Additionally, some seeds want warm weather to germinate and then thrive in the cooler weather whereas others need colder soil to germinate at all.
Here’s a list of our top recommended plants to grow in your fall and winter garden.
If you’re not a GrowJourney member or you’re also growing non-GrowJourney seeds, this soil temperature seed germinating chart can help you decide what your plants need.
Weird Weather? No Problem!
If you’re in an area where the summer is still raging hot when you’re supposed to be sowing crops for fall harvest, don’t worry. Your seeds aren’t that smart and you can trick them!
The most effective method is to pour ice water on your soil at dusk, plant your seeds in that spot, and then cover them with a thick board. Start checking after 3 days to see if there are tiny white sprouts underneath the board. Once the seeds sprout, the board needs to be removed so the sprouts can get sun. You can then put a little shade cloth above the bed to help them along until the weather cools down.
If you want to start winter plants when the soil is already too cold for outdoor germination, it’s time to start your transplants indoors. Other options: use a seed heating mat or put them outside in a warm cold frame. Then you can transplant established, 3-6 week old seedling into your covered low tunnels.
Watering Your Fall & Winter Garden
Fall and winter gardens typically require less water than spring/summer gardens since there is much less evaporation, but you’ll still want to make sure to keep up with irrigation. Hoses and drip lines freeze in the winter so you may need to do a bit of hand watering.
If you’re in an area that gets rain in the winter, always uncover your plants when the weather calls for rain if you’re using plastic row cover. The fabric row cover we recommend above allows rain through, so you won’t need to uncover your rows during rains.
Believe it or not, your cold-hardy plants can freeze solid if they are wet and then start growing again when they thaw out. Just make sure not to harvest or work your plants until they’re fully thawed–their frozen cells can shatter and burst.
Follow these winter gardening tips and you can walk right past the anemic winter vegetables in the supermarket and pick your own fresh, delicious varieties right outside your home.
Eliza @ GrowJourney