What to plant this week in International Falls, MN
In International Falls, the week of September 20 marks your absolute final deadline to pull up all summer crops before a hard freeze hits. With average lows plummeting toward -35°F and frost arriving on schedule, there is no room for error in securing your harvest.
The next 7 days
International Falls, MNGrowing in International Falls right now
- Tuck in cold-hardy perennials like Garlic, Borage, and Parsnip immediately if they haven't been planted, as ground temperatures will drop rapidly.
- Prioritize harvesting all warm-season items from the 'harvest_soon' list today; any remaining plants on the vine or bush will be killed by tonight's freeze.
- Apply a thick layer of straw mulch over your Winter Squash and Pumpkin beds to protect developing fruit from the biting October air.
- Do not attempt to transplant anything new this week in our short season; focus entirely on protection and final collection.
Sow this week
1 crops- Garlic
Transplant this week
Nothing is due to go out this week.
Harvest soon
29 crops- Beefsteak Tomato
- Borage
- Brussels Sprouts
- Bush Bean
- Carrot
- Cleome (Spider Flower)
- Cosmos
- Dahlia
- French Marigold
- Garden Geranium (Zonal)
- Garden Verbena
- Garlic
- Lantana
- Leek
- Ornamental Sweet Potato Vine
- Parsnip
- Petunia
- Pole Bean
- Potato
- Rutabaga
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Vinca (Madagascar Periwinkle)
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Clear away spent vegetable plants now to prevent disease carryover into winter.
- Divide perennials like borage, garden verbena, and zinnia while the soil is still warm.
- Gather all fallen leaves and debris from around your garlic patch to keep it clean.
Pest & disease watch
- Monitor for late-season aphids on remaining Pole Beans and Scarlet Runner Beans before frost kills them, as cold weather can stunt their natural predator population.
- Check your Zinnia and Cosmos stems for powdery mildew spores that may have built up during the humid summer; remove infected foliage to prevent overwintering issues.
Watering this week
Reduce watering significantly now that harvest is underway, allowing the soil to dry out between the last few waterings before frost.
Mark your tomato and pepper locations with stakes so you can easily find them when spring planting begins next year.
International Falls gardening questions
3Can I still transplant Garlic now in International Falls?
Yes, this is your last window to sow or plant hardy bulbs like Garlic before the ground freezes solid. Ensure you push them deep enough so they are fully covered by soil and mulch for insulation against our extreme winter lows.
How do I protect my Winter Squash from the upcoming freeze?
Harvest any mature squash immediately, but if some are still green on the vine, cut them off with a few inches of stem and cover them loosely with floating row covers or straw to delay frost damage by a day or two.
Should I leave my Borage and Garden Geraniums outside for winter?
Borage is hardy enough to survive our Zone 3b winters if the ground freezes, but you can add extra mulch around the base; Garden Geraniums (Zonal) are not fully hardy here, so bring pots inside or cut them back and heavily mulch the roots.
Other cities in zone 3b
4See the full zone 3b guide → · Plan your International Falls garden in SproutGuide →