What to plant this week in International Falls, MN
In International Falls, the deep freeze of late winter has officially broken enough to mark May 15 as your average last frost date, signaling that soil temperatures are finally climbing above freezing. However, with nights still capable of dipping near zero degrees well into spring, gardeners must remain vigilant against late-season chills before making any moves.
The next 7 days
International Falls, MNGrowing in International Falls right now
- The clay-heavy soils typical of northern Minnesota hold moisture tightly; avoid working the ground if it feels sticky to prevent compaction that harms root growth in cooler weather.
- While the calendar suggests a May 15 frost end, microclimates vary across the city's flat terrain; wait for soil warmth rather than relying solely on the date before planting cool-season crops.
- With no harvestable or transplant-ready items this week, focus your energy on preparing seedbeds and starting seeds indoors under grow lights to maximize the short growing window ahead.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
No harvest windows opening just yet.
Seasonal tips
- Apply fresh compost to beds now to warm the soil before the growing season begins.
- Clear winter debris from garden borders to prevent harboring late-season pests.
- Prepare hardy perennial beds by dividing crowded clumps if they are still dormant.
Pest & disease watch
- Watch for early outbreaks of cabbage loopers and armyworms as soon as brassicas emerge from cold soil.
- Slugs thrive in International Falls' damp spring conditions; set out beer traps or use iron phosphate baits to protect young seedlings from nocturnal feeding.
- Powdery mildew can strike immediately if plants are watered heavily at night before a temperature drop.
Watering this week
Water deeply only when snowmelt is insufficient, as frozen ground prevents absorption until the soil thaws.
Start indoor seedlings of cool crops like peas or lettuce now to be ready for transplanting in late May.
International Falls gardening questions
3When is the safest time to plant tomatoes and peppers outdoors in International Falls?
Do not rush these warm-weather crops out until after May 15, but be prepared for sudden cold snaps even then. Use row covers or cloches immediately upon planting to provide emergency protection against overnight temperatures near freezing.
Can I start my vegetable seeds outside now in the International Falls soil?
No, the soil temperature is currently too low for successful germination of most warm-season vegetables. Start your peas and lettuce indoors or wait until late May when the ground has warmed enough to support seedling growth without frost damage.
What specific crops should I focus on preparing this week given our short season?
Since no items are ready for harvest or transplanting yet, prioritize starting heat-loving plants like tomatoes and peppers indoors now. Focus your efforts on building a strong head start so you can get them in the ground just after May 15 to catch every possible day before the September 20 frost.
Other cities in zone 3b
4See the full zone 3b guide → · Plan your International Falls garden in SproutGuide →