What to plant this week in Quebec City, QC
Quebec City gardeners are racing against the clock with only four weeks before the average first frost on October 1, making this final sprint critical for harvesting heat-loving crops like watermelon and zucchini. While night temperatures can still dip into the -20s, your warm-season plants listed for harvest soon require immediate protection or collection to survive the approaching cold snap.
The next 7 days
Quebec City, QCGrowing in Quebec City right now
- Protect late-maturing pumpkins and winter squash with heavy row covers tonight, as Quebec's rapid autumn cooling can shock vines before they set hard rinds.
- Harvest garlic now while the foliage is still green; in this region, bulbs store best if pulled before a hard freeze turns leaves completely brown.
- Use the warmth of your greenhouse or cold frame to extend the season for basil and borage by covering them with fleece during any sudden temperature drops below 50°F.
- Check drainage in low-lying areas near the St. Charles River, as saturated soil from recent rains can cause root rot in edamame and pole beans right before harvest.
Sow this week
1 crops- Garlic
Transplant this week
Nothing is due to go out this week.
Harvest soon
44 crops- Basil
- Borage
- Brussels Sprouts
- Bush Bean
- Cantaloupe
- Celery
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Ghost Pepper (Bhut Jolokia)
- Gourd (Ornamental/Bottle)
- Habanero Pepper
- Honeydew Melon
- Leek
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Nasturtium
- Ornamental Sweet Potato Vine
- Parsnip
- Pole Bean
- Potato
- Pumpkin
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Tomatillo
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Begin succession sowing bush beans and cucumbers every two weeks for continuous yields through summer.
- Apply a fresh layer of mulch around established plants to retain moisture as spring temperatures fluctuate.
- Prepare your soil beds now that the danger of frost has passed to ensure optimal root growth.
Pest & disease watch
- Watch closely for aphid swarms on sunflowers and cosmos, which thrive in Quebec's humid summers but must be controlled before frost sets in.
- Monitor leek moths on your leeks and parsnips; larvae can devastate the crop just as you are preparing to pull them for storage.
- Inspect bell peppers and habaneros for spider mites, especially if there has been little rain this week, as dry heat favors these tiny pests.
Watering this week
Water deeply in the morning to encourage strong root development while minimizing evaporation and fungal risks.
Since garlic is being sown now, ensure you plant it a few weeks before your average last frost date of May 12 for a robust harvest next fall.
Quebec City gardening questions
3Can I still plant garlic in Quebec City now?
Yes, sow your garlic cloves immediately since they need several weeks of cool soil time to establish roots before the ground freezes hard. Plant them about 2 inches deep with the pointed end up for best winter survival rates.
How do I save my watermelon and cantaloupe before October 1?
Pull these vines as soon as the fruit reaches full maturity or even slightly past it, rather than risking a frost that will ruin the flesh. If you need to delay picking, wrap the melons in double layers of newspaper or burlap to insulate them from cold nights.
What should I do with my tomato and tomatillo plants right now?
Since transplanting is not an option this week, focus on harvesting any fully ripened fruit immediately while the days are still long enough for new growth. For unripe green fruits, bring them indoors in a sunny windowsill location to finish maturing off-season.
Other cities in zone 4b
3See the full zone 4b guide → · Plan your Quebec City garden in SproutGuide →