What to plant this week in London, ON
London, ON gardeners are officially in the final stretch of summer harvest as frost-free days wind down with an average first frost on October 17th. This week is critical for pulling late-maturing crops like Zucchini and Sweet Corn before night temperatures dip toward your zone minimum of -10°F.
The next 7 days
London, ONGrowing in London right now
- Protect young perennials like Dahlia and Shiso from the increasing chill by cutting them back or moving potted specimens indoors immediately.
- Soil remains warm enough to finish harvesting Bush Beans and Okra, but be ready for early snowfall if a late cold front moves through the Thames Valley this week.
- Heavy clay soils common in our region may become workable now, allowing you to prepare beds for next spring's Garlic planting while they are still manageable.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
41 crops- Basil
- Borage
- 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)
- Honeydew Melon
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Sweet Potato
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans and sweet corn every two weeks for continuous harvests through summer.
- Pinch back the tops of zucchini and squash plants now to encourage more fruit development rather than just vines.
- Cut back dying foliage on basil and borage after heavy harvesting to promote a second, smaller flush of growth.
Pest & disease watch
- Late-season aphids often cluster on tender leaves of Cosmos and Zinnia as plants seek moisture before dormancy; watch for rapid infestations.
- Powdery mildew can surge on Cucumbers and Melons during our typical humid autumn weather, so ensure good airflow between rows.
- Cutworms may still emerge in the damp soil to attack seedling stems of transplanted Fennel or Sunflowers if protection hasn't been applied yet.
Watering this week
Water deeply in the early morning to reduce evaporation while supporting heavy fruit production on melons and squash.
Pull any volunteer weeds immediately around your transplants like edamame and fennel before they compete for nutrients.
London gardening questions
3Can I plant Garlic now for next year's crop?
While this week is too late for optimal planting given our last frost date of April 21st, you can order bulbs to arrive in November. For immediate success, wait until the ground freezes naturally to prevent rot from wet soil.
When should I bring my Dahlias and perennials inside?
With first frosts averaging October 17th, dig up tubers like Dahlia before any hard freeze hits, or cover potted plants with frost cloth tonight. Don't wait for the -10°F zone minimum to arrive; act while temps are still above freezing.
How do I extend my Sweet Corn and Watermelon harvest?
Harvest these crops every two days as they ripen, checking that kernels are milky and rinds turn dark green or orange. Leaving them on the vine too long in our short season risks spoilage before the frost date.
Other cities in zone 6a
12See the full zone 6a guide → · Plan your London garden in SproutGuide →