Yes, You Can Have A Garden In December (Even In Cold Climates)

Imagine a holiday feast that includes fresh veggies grown in your backyard. Is it some kind of Christmas miracle? Do you need to ask Santa Claus for a house in Florida? Not at all. While most people think of veggie gardening as a warm-weather hobby, you can have equally bountiful harvests when the view outside looks like the perfect Christmas card. Don't believe me? Well, my garden in Toronto, Canada (growing zone 7a on the Canadian hardiness scale) is your proof. How is it possible? Let me explain. 

If you want to have a still-thriving garden during a colder month like December and even into January, it comes down to three factors: the right timing, the right care, and the right plants.

Nothing actually grows in December, so let's get that out of the way. Instead, think of your garden as an outdoor refrigerator full of living produce you can keep picking. The late-summer and fall months will be used to get cold-tolerant plants to full size before the days become too short and cold to support plant growth. Depending on your growing zone, the end of the growing season could be anywhere from late-October through late-November.

To grow cold-hardy crops successfully, you're going to need to start your own plants from seed. Nurseries and garden centres cater mostly to summer gardeners, and won't have the right plants available at the time you need them to grow into the fall. Instead, by sowing from seed you'll have a much wider choice of varieties and more control over the plant's growth.

For every see package, get familiar with the days-to-maturity information on the back and work backwards from your first fall frost date for a good idea of when you need to sow and transplant them into the garden. Considering the time of year and variability of weather, you'll want to add about 25-30% more days to that timeline than what is listed, This will help compensate for less than ideal growing conditions through the later months. For example, give fall-sown radishes an extra 7-10 days compared to the 28-30 that they would normally require with more sun and warmer temperatures. Succession planting is a good way to make this all work in your garden. As one area of the garden becomes available during the summer, use that space to grow something else. Here's an example. 

Every plant will have its natural limit of cold tolerance, so being able to protect your garden will help maintain your harvests later into the year. Frost blankets, mini greenhouses called polytunnels, plastic cloches and other barriers act to trap warm air and provide relief from unfavourable conditions. The general rule is that every layer of protection is like growing in one zone warmer on the scale. And every zone warmer is about two weeks of extended season. So, the more of these you can combine, the better. Cloches over heads of lettuce, underneath a clear plastic tunnel is the equivalent of moving my garden from southern Canada to central Tennessee or Virginia. 

What plants should you be growing? Short of having a heated greenhouse, no plant that fruits will ever be suitable for a late-season gardening. But there are still many cold-hardy veggies that you can have. Here are a few of my favourites for to consider, why they do so well and some care tips to help you. 

Root veggies: carrots, leeks, radish, beets

• Growing deep beneath the soil protects them from cold and even an early snowfall won’t cause harm (for a short time, the blanket of snow actually protects them further. See for yourself)
• Add a layer of hay or shredded leaf mulch to provide extra insulation 
• Consider growing them in raised beds which maintains soil warmth
• Even if the top of the plants die from the cold, the root stays alive and is harvestable
• Longer to mature options like carrots and leeks can be seeded in spring and left in the ground through the rest of the year, or they can be re-seeded in mid-summer as the late-fall and winter crop
• Harvest these plants as needed until the ground freezes solid for more than 72 hours

Leafy greens: rapini, lettuce, Swiss chard, spinach, let’s include kale here too (even if it’s technically another family of plants)

• Choose the right varieties that are most tolerant to cold weather and sow them in late-summer for transplanting. Sowing fast-growing types too early may cause them to stress and flower, rather than slowing their growth
• Harvest leaves and shoots from the outside as they grow, to encourage more growth into the latest part of the season
• Erect a simple tunnel frame and cover with clear plastic or frost blankets when nighttime temperatures are going below -3°C / 26°F
• They might look limp and frozen after a blast of cold, but they will thaw out and bounce back on warmer days for harvesting
• For even deeper cold protection build a cold frame over the plants using an old window 
• If their roots are left in the soil over winter, there's a good change they will regrow new leaves in spring for another harvest

Hardy herbs: parsley, oregano, rosemary 

• These will withstand some cold, but not long periods of it
• If potted, dig a hole and bury the pot into the ground or in the soil of a raised garden bed to insulate the roots longer
• Erect a simple tunnel frame and cover with clear plastic or frost blankets when nighttime temperatures are going below -3°C / 26°F
• Enjoy them fresh by picking the outermost branches as long as the weather permits
• When winter is settling in for good (daytime temperatures are not staying above freezing), harvest the entire plant

Celery, celeriac, fennel

• More sem-hardy than fully cold-hardy, these will only withstand freezing above -3°C / 26°F, and not for more than 24 hours without protection
• Unlike leafy greens, if these freeze solid it can ruin the stems, so harvest them more aggressively ahead of cold weather

Brassicas: broccoli, cauliflower, brussel sprouts, cabbage

• Some varieties will need to be sown and transplanted as early as May or June in order to mature for late-fall
• Protect these plants with insect netting as they establish, which can then be changed to clear plastic or frost covers as needed
• Exposure to a light frost will actually improve their taste and remove bitterness
• Harvest them as soon as they are mature, but they can also be enjoyed if not grown to full-size
• For Brussel sprouts, consider 'topping' the plant by pruning new growth at the top approximately a month before the growing season ends to encourage full formation of the sprouts further down the stalk

Every garden and gardener is different. So is the weather every year. If you do decide to extend your growing season into colder months, find the right plants and set up that you'll enjoy. And if you're looking for some personalized coaching and planning, I can help either n-person or virtually. As you grow more and more, remember not to get discouraged by failures, and also be flexible to change up what was successful. You might have the only yard on the block harvesting long after the leaves have changed colours and dropped, so no matter what you pick be proud of it. 

Buon giardinaggio!