There are plenty of reasons why you might want to know whether kale, Brassica oleracea, the star of many a spring or fall veggie garden, is an annual or a perennial.Armed with this knowledge, you will be able to answer some of the other questions you may have about growing this cruciferous crop in your garden.Can you harvest and save seeds from it the first year?For gardening purposes, it’s important to know that annuals must be replanted every year, while longer-lived perennials will keep growing year after year.Some kale varieties are perennial, and I’ll get to them later, but most varieties are neither an annual nor a perennial.In USDA Hardiness Zones 7-10, biennial kale will continue to produce edible leaves throughout the winter.Shortly after your plants start flowering, you’ll begin to see long, slender seed pods developing. .
Overwintering: Crops that can withstand the cold and how to help
It’s officially dark at 5pm and it’s time to clean up your garden for winter.You won't be reaping huge harvests over the winter, but once the day length increases to 10 hours a day in the early spring, these plants will start to grow again, often providing an abundant spring harvest well before spring planted crops have even been put in the ground.The good news is that it is easy to choose which crops to overwinter and there is very little work to do besides harvesting, protecting plants from frost and watching out for pest damage.There is nothing that bolsters your spirits on a cold, dark winter day like harvesting your own fresh salad or cooking greens, reminding you of the full, diverse harvests to come again in spring.Of this group, the most cold-hardy and reliable are Cabbage, Fava Beans, Kale, Mustard Greens and Spinach.Every year we successfully overwinter these crops in our Seattle gardens, without any sort of protection. .
Make Room for Kale - How to Grow Kale
Because kale is a biennial crop that generally takes two seasons to produce flowers and seeds, it will take time for the seed industry to catch up to the trend.Varieties include Meadowlark, Westlander, Dwarf Green Curled, and the vigorous, frosty-purple Olympic Red.If you haven't tried them before, consider the Russian and Lacinato types as well: Red Russian and White Russian offer exceptional cold-hardiness and have a tender texture that's excellent for steaming and stir-fries.A Kale for Every Gardener.Each year the farmers at High Mowing Organic Seeds plant new varieties in side-by-side trials with classic favorites.In situations where space is limited, such as for gardeners growing kale in raised beds or large containers, look for varieties described as compact and productive.For baby greens (leaves harvested 20 to 30 days after planting) my favorites are Red Russian, White Russian, and Vates, a very compact variety ideal for late-season salads and overwintering.Direct sow seeds every one to three weeks throughout the summer for a continuous harvest of baby leaves.Two weeks before your last frost, start some Meadowlark curly kale and heat-tolerant Lacinato for summer salads and early fall soups.Finally, about eight weeks before the first fall frost, start seeds of vigorous, frost-tolerant Olympic Red and Vates for fall and winter harvests.And since I'm writing about kale (and getting hungry), here's a recipe for a delicious Three Greens Gratin you can make with kale for a satisfying winter meal. .
Kale: The Workhorse of Your Winter Garden
In her bestselling “Book of Kale,” Master Gardener Sharon Hanna reminds us that “kale has come a long way from being a throw-away garnish from the side of our plates.Here are ten reasons to make kale a staple in your winter garden. .
Recommended Crops & Varieties
The plant builds up sugars in response to cold, which protect its cells from bursting in freezing conditions.To optimize germination rates when it's warm at seeding time, irrigate before planting, to cool the soil.To ensure your desired plant density, you can alternatively start spinach in plugs or paperpot trays and grow to transplant size (two true leaves).Some growers configure LED-lit racks or shelving units in their basements to provide a conveniently cooler, indoor seed-starting environment at this time of year.For example, mâche planted in late September in the tunnel here in Maine is typically ready to be harvested in January and does not bolt until early March, while claytonia becomes full and beautiful as it emerges from the Persephone period, with lovely little flowers.Radicchio types (Cichorium intybus), however, shine in the winter tunnel, with superior cold-tolerance, eye-catching colorations, patterns, and shapes, and sweeter flavors that are not always as achievable at other times of the year.Young radicchio planted in the fall, unheated tunnel can likely overwinter with just a single layer of row cover.By late February they will start rapid regrowth, offering an extra-early harvest of unique, tasty greens to add to the mix.With mild flavor and tender leaves, overwintered cilantro lends itself well to harvesting at baby leaf maturity.We used 1–3 layers of row cover, but have a temperature monitor under the rowcovers, and it got down to the high teens on several nights.We used 1–3 layers of row cover, but have a temperature monitor under the rowcovers, and it got down to the high teens on several nights.Lettuce is less cold-hardy than many greens, and fares best in a partially heated greenhouse or under a low tunnel within an unheated hoophouse.We suggest harvesting the lettuces before they're required to endure the coldest temperatures post mid winter.We also note the young leaves of salad mix tend to be less susceptible to freeze damage than mature lettuce heads.Recently, growers in the north have been reporting some success with Salanova lettuces grown for mini head production and cut-and-come-again (CCA) salad mix in unheated high tunnels.One limiting factor in high tunnels is the filtering of sunlight that decreases the vivid red color of some lettuce varieties.Plant enough seed to provide for a long winter-harvest period, and lay row cover over the crop if flea beetles are a problem.In addition, they are orange — unlike most fresh winter-harvest crops — adding a welcome touch of color to the produce you offer for sale.A display of bunched carrots with attractive tops brightly signals freshness to prospective customers.Carrots can also be successfully overwintered as young plants, to grow and reach harvest size in early spring.Bunching onions, which include scallions, can be grown for spring harvest but require ample lead time.In Quick Hoops trials at our research farm in Albion, we have found that 'T448,' 'Bridger', and 'Desert Sunrise' are great for this application. .
A Winter Greenhouse: How to Harvest Vegetables All Winter
This unheated structure, which is also featured in my book, Growing Under Cover: Techniques for a More Productive, Weather-Resistant, Pest-Free Vegetable Garden, captures solar energy and shelters a wide variety of cold tolerant crops like kale, carrots, leeks, scallions, carrots, and spinach.Just because I use a winter greenhouse doesn’t mean that I don’t use other winter structures in my garden.There are many sizes, shapes, and types of walk-in structures that can be used to winter harvest cold season vegetables and herbs from a backyard garden.Whatever type of greenhouse you decide to buy or build, they all have two main components: a frame and a transparent cover.In winter, that weather includes frequent storms that bring heavy snow, freezing rain, and strong winds.When deciding on a type of greenhouse, look first at your site, space, and climate.Most urban yards won’t have space for a large hoop greenhouse, but a small glass or polycarbonate-glazed structure may fit.Consider your climate and extreme weather.What to grow in a winter greenhouse.I garden in zone 5 and have winter temperatures that can go down to -4 F (-20 C).By late winter most of the crops inside my greenhouse have been harvested.Any empty growing space is amended with compost and seeded with fresh greens and root crops for early spring harvesting.When to plant winter vegetables.Most of the vegetables in my winter greenhouse are planted mid-summer to mid-autumn.My Napoli carrot crop, for example, takes about 58 days to go from seed to harvest.However, as the day length shrinks in autumn, plant growth slows, so I always add on an additional 7-10 days when planting crops for late fall and winter harvesting.If you wish to have mature kale or collard plants for winter harvests, these take around 70 days from seeding, so plan accordingly.They need about 55 to 70 days to go from seed to harvest.To insulate, I use deep mulching, row cover fabrics, or polyethylene covers floated on mini hoops.To use fabric or polyethylene covers over beds of greens, hardy herbs, scallions, and other vegetables, I float the covers on top of simple wire hoops.Watering is reduced to once or twice a week in early to mid-autumn when the days get shorter and the temperatures begin to drop.In winter, I don’t water unless we get a few days of thawing temperatures.The inside of a structure heats up quickly, and it’s best to grow winter crops on the cool side to promote hardy growth.This is because the inside temperature is typically warmer than the outside temperature and I’m sheltered from winter winds.This works because my structure is covered with polyethylene.With a polycarbonate or glass-covered greenhouse, you need to gently brush the snow off the panels from the outside. .
5 Vegetables You Can Harvest All Winter Long
We recommend sowing a succession of radish plantings every two weeks from early spring through fall for a continuous harvest of these crisp garden treats.Fresh radishes can be a reminder of spring on even the gloomiest winter days.If you plant now, you can harvest and thin at the same time, whenever you feel like it, all winter long.As with radishes, a fluffy layer of mulch should be plenty to protect your overwintering carrots, but a cloche or floating row cover can’t hurt.Treat your overwintering beets just like you would carrots.Plant a little more densely than the seed packet or plant tag recommends, protect them with mulch, harvest small beets and beet greens all winter, and then watch the remaining plants take off in the spring.Mixed Baby Greens.Now is the perfect time to plant greens for fresh, fancy salads all winter long.You can buy salad green mixes as either seeds or starts, make your own mix by combining your favorite leafy green varieties, or plant separate rows of each variety and mix them post-harvest.Harvest as much as you need, and leave the rest for the next harvest.Like other overwintering vegetables, kale gets much sweeter in the winter.If you start from seeds, you might want to consider them part of your baby greens mix. .