When to transplant cold-hardy plants like broccoli, lettuce, and spinach, as well as direct sowing seeds for these plants?

Deciphering the terms “once the soil can be worked” and “once the soil reaches temperature” found on many seed packets has different meanings for cold hardy plants. 

The “once the soil can be worked” or “once the soil reaches temperature” advice typically applies to both direct sowing seeds and transplanting seedlings. Cold-hardy plants can generally tolerate cooler temperatures, so it’s often safe to transplant seedlings or sow seeds directly around the same time. However, there are some considerations to keep in mind when transplanting seedlings:

Reotemp 12 Inch Soil & Compost Thermometer with Digital Composting Guide

Inkbird IBS-TH3 WiFi Digital Thermometer Hygrometer, Indoor Outdoor

Gardening Shortcut Links

Square Foot Gardening Section

Hardening off: Before transplanting seedlings outdoors, gradually acclimatising them to the outdoor environment is essential. This process is called “hardening off.” Start by placing your seedlings outside for a few hours per day, gradually increasing their time outdoors over a week or so. Ensure they’re protected from direct sun, strong wind, or heavy rain during this period.

Soil temperature: Although cold-hardy plants can tolerate cooler temperatures, they will still grow best if the soil temperature is within their optimal range. For broccoli, lettuce, and spinach, this is typically around 45°F to 65°F (7°C to 18°C). A soil thermometer can help you determine if the soil temperature is suitable.

Frost protection: While cold-hardy plants can handle light frosts, it’s a good idea to have some frost protection measures in place, such as floating row covers or cloches. These can be particularly helpful when transplanting seedlings, as they’re more vulnerable to cold damage than established plants or seeds.

Weather conditions: Pay attention to the local weather forecast and avoid transplanting seedlings during extreme cold or wet periods, which can stress the young plants.

You can generally transplant cold-hardy seedlings around the same time as sowing direct seeds. Still, it’s essential to harden them off, monitor soil temperature, and provide protection from frost and harsh weather conditions.


Seeds and planting
Links and Resources

Recommended Products
(These are some of what I use)

These nursery bags
These Grow bags


mybackyard.ca Seeds Page
Get a Head Start on Spring: The Benefits of Starting Your Seeds Indoors
Saving Vegetable Seeds: A Comprehensive Guide to Gardening Success
myBackyard.ca Planting Guide
Pollock Tomatoes (North hardy Tomato variety)
Tomatoes (Useful information on starting tomatoes from seed)

DIY Garden Irrigation System: A Detailed Guide for Northwest Ontario

Blog Posts

When to start planting seeds
Germination testing your seeds
Looking for sources for seeds?
Heirloom seeds
Chitting your way to more potatoes
So it's before the first frost; what can I plant?


Individual seed and plant information is available in the  "Gardening Shortcut Links" above under "North Hardy Plants to grow". I have successfully grown all of these, and most I grow year to year.







myBackyard is for recreational purposes only. Plants, mushrooms and berries cannot be 100% identified through this website alone. It is up to the reader to properly identify plants, fungi and trees. Some wild plants, berries and mushrooms are poisonous or can have serious adverse health effects. Even those listed as edible may cause adverse reactions in individuals.

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