By Lindsay Graves, Eagle County CSU Extension Master Gardener
Homegrown arugula in January? At 6,700’? Yep! With some low tech season extension techniques, the hardiest salad greens will overwinter in much of Colorado, so you can enjoy tasty treats in winter and early spring harvests before many gardeners can even plant!
Once you become accustomed to the taste and heft of homegrown leaves, you won't want to go back to store bought.
Let’s consider the challenges:
Harvested in fall but planted in summer. Our space is typically filled with summer veggies. Where will the greens go?
Certain vegetables have adaptations to help them survive. Some concentrate sugars in their tissues to lower freezing point; some have extra space between their cells so ice crystals don’t cause as much damage.
Between Nov 15 and Feb 1, days are too short for much growth, so the plants are in basically a waiting state. When growing fall greens, we have two options: grow them to near full size and hold for fall + early winter harvest, or grow them to a small size and overwinter and resume growth in the spring for late winter + early spring harvest.
When the ground is frozen, plants can't drink water. Our dry winds pull moisture out of their tissues.
While formidable, the challenges can be overcome. Let’s check out the solutions.
Incorporate a patch of cold season greens in your planting plan. They can follow the first planting of greens, peas, or garlic. You'll want to plant in mid July for fall harvest and early Sept for spring harvest (in my garden at 6,700’).
Starts vs Seeds
Using starts is a great idea! Planting a 4-6 week old plant vs a seed saves you time and space. It can be hard to source seedlings in summer, so start your own. Seeds will work too though if you don't want to grow starts.
Row covers provide a more even temperature and allow plants to start growing earlier in the morning and later into the evening, so they can size up quickly. Add a row cover after day time highs drop below 85. Add plastic over the row cover when heavy snow threatens (so it doesn't rip the row cover). Plastic must be vented daily until the highs are below 60.
Lettuce- winter density
Spinach-Space for fall harvest
Winter Bloomsdale for spring harvest
The Fall Greens Gardener’s Year-round Checklist
Add cold season greens to your planting plan
Order cold tolerant varieties with your seed order
Clean your seed starting kits thoroughly after their first round of use
Replenish any seeds starting supplies that were used up
Harvest something to make space for greens
Apply a rich compost (like worm castings)
Sow greens (in ground or in starting kits). Make last sowings by Sept 15.
Cover (row cover after day highs below 85, plastic after day highs are below 60)
Harvest greens on warm days when leaves are not frozen. They will resume growth after Feb 1.
|My cabbage in October|
|My lettuce in October|