Extending your growing season is one of the best ways to get more from your garden, especially in short season climates.
I know because I’ve been doing it for years in our zone 5 Canadian climate, even with the heavy wet snowfalls and temperatures that dip down to -20C/-4F.
Although it may seem like a lot to learn at first, and requires some financial set up costs, using season extenders in your garden is really worth the investment. Anything that helps you grow food year round is a good thing right? The ability to grow year round does depend on your climate, but as you’ll learn in this article there are many crops under season extenders that can add weeks to your growing season. I’ll also discuss overwintering veggies and growing indoors if season extending isn’t for you!
The best time to season extend is in the spring and fall, and if you’re feeling extra adventurous, the winter months even with the snow.
(be prepared for a work out shoveling snow!).
Crops to Grow in Season Extenders
Believe it or not, there are many crops that can handle frosts, harder freezes and snow. Some even without protection! (Learn 10 crops more cold hardy than kale).
Selecting the right varieties is very important when season extending.
The days get hotter and longer in the spring so you’ll want to choose cool season crops that are bolt-resistant in the spring. In the fall and winter you’re selecting varieties that are cold hardy as the days get colder with shortened daylight.
Lettuce for example is not very cold hardy but if you grow varieties like ‘Rouge D’hiver’ or ‘Winter Density’ you can harvest in the colder months under tunnels. The same thing goes for springtime, choosing bolt-resistant varieties will help with the increasing heat.
Cool Season versus Cold Hardy
Cool season vegetables thrive in cool temperatures but are less likely to withstand light or hard frosts. Cold hardy vegetables can handle light or hard freezes, and may even overwinter under the snow for a spring harvest. Now this does depend on your climate & growing zone.
List of Cool Season Vegetables
Arugula, beet, broccoli, cauliflower, cabbage, celeriac, chinese cabbage, carrots, chard, chicory (endive, frisee and radicchio), collards, fava bean, Florence fennel, garlic, shallots, kale, leek, lettuce, mizuna, mustard, spinach, mache, mesclun greens, onion, pak choi, parsnip, pea, potato, radish, rutabaga, salsify, tatsoi.
Here are some Cold Hardy Crops
- Brussels sprouts
- Swiss chard
The cool season and cold hardy vegetables both benefit from added mulch, mini hoop tunnels, cold frames, greenhouses or heavyweight row covers.
Root veggies often taste sweeter after heavy frosts.
We’ve grown carrots, parsnips, turnips and beets for a fall harvest and have left them without protection (although mulching would extend the harvest). We’ve even harvested potatoes that were deep in the ground all winter and harvested in the early spring before they sprouted.
Building & Using Season Extenders
Using season extenders might take a little practice but I promise you they’re worth the time to learn (plus the start up cost).
Here’s some info on building & using season extenders:
- How to Build a Low Tunnel
- Benefits of Using Row Covers
- Use a Polytunnel to Extend the Growing Season
- 14 Ways to Extend Your Growing Season
- Use a Polytunnel to Extend Your Growing Season
- Is Plastic Necessary? Success with Fabric Row Covers
- How to Build a Small Polytunnel
- How to Build a Polytunnel Greenhouse
- Year-Round Veggie Gardener
- Clever Cloches
- Garden with Cold Frames to Grow More Food
- Cold Frame Gardening
- How to Start Seedlings in a Cold Frame
- The Benefits or Row Covers
One of the most important things to remember is to vent your season extenders, the very thing that allows you to keep your crops warmer on the colder days can also get too hot. Venting is key to allowing good airflow and making sure your plants aren’t stressed from the heat; many cool season plants can’t handle and may even try to go to seed (bolt). The image below from Fix.com gives you a good idea of venting, although I strongly disagree with the row cover not needing venting; they definitely do and should be closed at both ends when it gets cold/below 0. In general temperatures above 3C/37.4F needs venting, especially with sunshine. I often don’t put season extenders on until it dips below 0 in the fall to make the plants stronger for the winter.
Tips for Season Extending
- Practice getting the right sowing times and varieties. Every local climate will be different and need slight adjustments. I use this table from West Coast Seeds as a guideline for sowing and transplanting times. Learn when to sow your seeds and start your transplants here.
- Use transplants to get a head start in the spring and fall. Your crops will especially come sooner in the spring with transplants under tunnels!
- Succession sowing every week over multiple weeks will help you get the right timing for your crops. You may get heat waves in the spring and fall which cause your plants to bolt. Sowing multiple times helps you still get crops that don’t go to seed.
- Restore the soil! Season extending means you’re growing more crops in a single growing season. It’s important to make sure you restore the soil in-between sowings otherwise your crops won’t have enough nutrients to grow. This is especially important in the fall because they need to grow fast before the cool weather sets in and because of Persephone days.
Planning your Fall/Winter Garden
Planning and timing is just as important as which varieties you plan to grow in your fall garden. Here are some great posts on how to plan your fall garden:
- How to Plant Your Fall Garden
- Planning (& Planting) the Fall Garden
- Fall/Winter Gardening Planting Chart
- What Gardening Zones & Frost Dates Tell You
- Cheating Winter: The Little-Known Truth about Frost and Freeze Tables
- Calculating Your Garden’s Persephone Days
- Winter Vegetable Planting Dates
- Planting Your Fall Garden
Can you Really Grow Food 365 days a year?
YES. Even with a zone 2 climate, you can grow indoors if you’re not up to/it’s too cold to garden outdoors!!
- Growing Popcorn Microgreens
- Grow Indoor Herbs: 5 Herbs that Thrive Inside all Winter
- Fast Growing Microgreens for Winter Salads
- How to Grow an Indoor Garden
- Growing Lettuce Indoors in the Winter
- How to Grow Sprouts at Home
- Grow Herbs at Home with a Windowsill Garden
- More Indoor Gardening on Pinterest
Get spring greens early by foraging, perennials and overwintering
- Spring Wild Edibles
- Best Vegetables to Overwinter in Zone 5
- Perennial Vegetables to Grow
- More early Foraging on Pinterest
Source: Fix.com Blog
Season extending can give you weeks more growing time in your garden. I’ve been doing it for years now, experimenting with different varieties and season extenders in our colder northern climate and I can tell you it’s amazing to harvest green food when there’s snow on the ground!
Do you season extend? What are your favorite season extenders and cold hardy varieties to grow?
Hungry for More Season Extending Info?
Great Winter Gardening Books:
Here’s some tips on how to get your garden beds ready for next season:
- Cover Crop Guide
- Putting Your Vegetable Beds to Bed
- What a Load of Manure
- Making a Leaf Mold Blanket
- Use Cover Crops to Improve Your Soil
- Green Manure Crops
- How to Put Fall Leaves to Work
- Clean Up Your Garden by Free-Ranging Your Chickens
- Putting the Garden to Bed
- Preparing Your Garden for Winter
- 4 Reasons to Improve Garden Soil
- Fall: The Perfect Time to Build Healthy Soil
- Fall Leaves: A Valuable Soil Builder
- Make Your Own Top Soil for New Beds
Source: Fix.com Blog
Source: Fix.com Blog