Roseau County, MN — Planting Guide
This month in Roseau County, Minnesota
Welcome to May in Zone 3b. These are the moves that will have the biggest impact on your growing season.
-
Get kale, lettuce, and angelica in the ground
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Plant carrots, kale, and lettuce from seed, right in the garden
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
-
Start harvesting microgreens
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
June prep starts now
- Transplants going out: cucumber, peppers, and pole beans
- Direct-sowing: cucumber, green beans, and peppers
- First harvests: lettuce, radish, and arugula
- Fall sowing: carrots, kale, and lettuce
Roseau County is in USDA Zone 3b. The average last spring frost is May 21 and the first fall frost is September 22, giving you a growing season of approximately 124 days.
At an elevation of 655 ft, Roseau County receives approximately 32 in of rainfall annually. Summer highs average 79°F with winter lows around -8°F. The predominant soil type is Silt Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 36 days year to year — ranging from April 28 in warm years to June 4 in cold years. The growing season is trending shorter by about 1.91 days per decade. Roseau County scores 61/100 (Good) on the Microclimate Index.
🌡️ Zone
3b (°F to °F min)
❄️ Last Frost
May 21
🍂 First Frost
September 22
📅 Growing Season
124 days
⛰️ Elevation
655 ft
🌧️ Annual Rainfall
32 in
Monthly Watering Calendar
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 1.2 in | 8 days | — | None |
| Feb | 1.6 in | 7 days | — | None |
| Mar | 1.8 in | 7 days | — | None |
| Apr | 2.9 in | 10 days | — | None |
| May | 3.9 in | 11 days | 0.4 in | Low |
| Jun | 4.3 in | 10 days | — | Low |
| Jul | 3.8 in | 8 days | 0.5 in | Low |
| Aug | 3.7 in | 9 days | 0.6 in | Moderate |
| Sep | 2.4 in | 8 days | 1.9 in | High |
| Oct | 2.7 in | 7 days | — | None |
| Nov | 1.9 in | 7 days | — | None |
| Dec | 1.7 in | 7 days | — | None |
Annual total: 31.9 in. Water needs vary by crop — tomatoes need ~1.2"/week while herbs like rosemary need only 0.3"/week. Check individual plant pages for crop-specific water budgets that factor in your county's rainfall and soil drainage.
Roseau County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.2
Drainage
Well Drained
Frost Risk Probability
Based on 31 years of NOAA weather station data from 3 stations
Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.
How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.
| Planting Strategy | Last Spring Frost | First Fall Frost | Frost-Free Days |
|---|---|---|---|
| Conservative (safest) | Jun 4 | Oct 8 | 126 days |
| Cautious | May 28 | Sep 28 | 123 days |
| Average year | May 21 | Sep 22 | 124 days |
| Optimistic | May 11 | Sep 14 | 126 days |
| Aggressive (risky) | Apr 28 | Sep 7 | 132 days |
Not very — frost dates can vary by ±36 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
Yes — growing seasons are getting shorter here (about 1.9 days per decade). Use the "Conservative" dates and choose fast-maturing varieties.
Gardening Difficulty Score
Roseau County offers good growing conditions. A little planning around frost dates goes a long way.
Local Gardening Help in Roseau County
Free expert help is closer than you think. Your county's cooperative extension office connects you with trained gardeners, soil testing labs, and local programs — all specific to Roseau County's climate and soil.
County Extension Office
Roseau County University of Minnesota Extension Extension Office
Phone: 612-625-8173
Visit Extension Office Website →
Extension offices are run by land-grant universities and funded by the USDA. Their advice is free, research-based, and tailored to your county's specific conditions.
Master Gardener Program
Free gardening help from trained volunteers
Master Gardeners are community volunteers who complete 40–60 hours of university horticultural training. They answer gardening questions, diagnose plant problems, and offer workshops — all free.
Many extension offices run a Master Gardener hotline where you can call or email with photos of plant problems for free diagnosis.
Soil Testing
Available through your extension office
Before amending your soil, get it tested. Your extension office offers soil testing (typically $10–$25) that tells you exact pH, nutrient levels, and amendment recommendations specific to what you want to grow.
Services Available in Roseau County
Finding local nurseries & garden centers in Roseau County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Roseau County's soil and climate that big-box stores can't. Plants from local growers are typically hardier because they're already acclimated to your zone.
How to Find Them
Search for "nurseries near Roseau County MN" or "garden center Roseau County" on Google Maps. Also check with your extension office — they often maintain lists of reputable local nurseries and plant sales.
Community gardens & gardening groups
Community gardens are a great way to learn from experienced gardeners in your area, especially if you're limited on space. Search "community garden Roseau County MN" or check your extension office and local parks department. Facebook groups like "Roseau County Gardeners" or "Minnesota Gardening" are also excellent for local advice and plant swaps.
What to Plant After Your Harvest
After your first crops finish, use the remaining frost-free days to grow a second round.
Sunlight & Day Length
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Longest Day
15.9 hours
Summer solstice daylight
Shortest Day
8.1 hours
Winter solstice daylight
Peak Sun Hours
10.1 hr/day peak (summer)
Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.
Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.
View detailed monthly data
| Month | Daylight Hours | Peak Sun Hours | Day Length |
|---|---|---|---|
| January | 8.5 hr | 3.3 hr | Short day |
| February | 9.9 hr | 4.5 hr | Short day |
| March | 11.6 hr | 5.8 hr | Short day |
| April | 13.5 hr | 7.3 hr | Neutral |
| May | 15 hr | 8.3 hr | Long day |
| June | 15.9 hr | 9.4 hr | Long day |
| July | 15.6 hr | 10.1 hr | Long day |
| August | 14.2 hr | 9 hr | Long day |
| September | 12.3 hr | 7.4 hr | Neutral |
| October | 10.5 hr | 5.5 hr | Short day |
| November | 8.9 hr | 3.7 hr | Short day |
| December | 8.1 hr | 3.1 hr | Short day |
Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.
Soil Temperature & Composting Calendar
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
Plant Warm Crops When
Soil reaches 60°F+
Soil warm enough from Jun through Aug.
Best Month to Compost
Jul
Microbial activity peaks when soil is warm.
Active Composting
5 months
Solid season. Piles go dormant in winter.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 6°F | 18°F | ❄️ Dormant | ~36 weeks |
| Feb | 10°F | 17°F | ❄️ Dormant | ~36 weeks |
| Mar | 17°F | 21°F | ❄️ Dormant | ~36 weeks |
| Apr | 35°F | 34°F | ❄️ Dormant | ~36 weeks |
| May | 51°F | 46°F | ♻️ Active | ~14 weeks |
| Jun | 63°F | 56°F | ♻️ Active | ~14 weeks |
| Jul | 70°F | 62°F | 🔥 Peak | ~8 weeks |
| Aug | 71°F | 64°F | 🔥 Peak | ~8 weeks |
| Sep | 59°F | 60°F | ♻️ Active | ~14 weeks |
| Oct | 48°F | 48°F | 🐢 Slow | ~24 weeks |
| Nov | 30°F | 36°F | ❄️ Dormant | ~36 weeks |
| Dec | 16°F | 25°F | ❄️ Dormant | ~36 weeks |
Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.
Pest & Disease Pressure in Roseau County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Insect Pest Pressure
Moderate — common pests appear but manageable with monitoring.
Disease Risk
Low disease risk — dry conditions reduce fungal problems.
Seasonal Risk
View 3 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | Moderate | Jun, Jul, Aug |
| Cabbage worms | Moderate | Jun, Jul, Aug |
| Slugs | Low | May, Jun, Jul, Aug |
Organic pest management tips
- Maintain healthy soil with regular compost additions to build natural pest resistance
- Practice crop rotation annually to break pest cycles
- Encourage beneficial insects with flowering herbs like dill, fennel, and yarrow
Cover Crops for Roseau County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Spring Cover Crops (2 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | May 29 | Jul 14 | — | Rapid growth, attracts pollinators, suppresses weeds |
| White clover | Apr 23 | Jul 14 | ✓ Yes | Living mulch, fixes nitrogen, permanent ground cover |
Summer Cover Crops (1 options) — Fill gaps and suppress weeds between plantings
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Sunflowers | Jun 18 | Sep 1 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Fall Cover Crops (3 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Oats | Aug 18 | May 7 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jun 22 | Apr 30 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jun 27 | May 7 | — | Erosion control, weed suppression, good biomass |
Wind & Microclimate
Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.
Seasonal Wind Speed
Spring: 11 mph Summer: 10 mph
Fall: 12 mph Winter: 13 mph
Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
6.5/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
Low
Relatively flat terrain (93 ft range). Frost pocket risk is minimal — garden placement is flexible.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
15,898 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
6 rain barrels (55 gal each)
For a typical 500 sq ft garden. Serious collectors: consider a 1,750 gal tank.
Legal Status
Unrestricted
Rainwater harvesting is fully legal in your state with no restrictions.
Best Collection Months
May, Jun, Jul, Aug
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Jan, Feb, Dec
Dry months when you'll rely on stored water — size your storage for this gap.
Rainwater collection tips for your area
- Your county receives approximately 31.9 inches of rain per year
- A 1,000 sq ft roof can collect roughly 15,898 gallons annually
- Rainwater harvesting is fully legal in your state
- Stock up on stored water before your dry season (Jan, Feb, Dec)
- Use a first-flush diverter to keep roof debris out of your collection
Soil & Growing Conditions in Roseau County
Soil Type
Silt Loam
Soil pH 5.9–7.2 · Well Drained drainage
Native soil is well-suited to most vegetables and herbs with regular compost additions.
Watering Needs
Drought stress: 5.5/10
Moderate drought pressure. Drip irrigation and mulching are highly recommended to maintain soil moisture through summer.
Season Tips
124-day frost-free season
A short season means indoor starts are critical for warm-season crops. Prioritise cold-hardy, fast-maturing varieties and use row covers to extend autumn harvests.
Your Free Printable Garden Planner
Plan every bed, every planting, every harvest — in one place. This 24-page printable includes your zone's planting calendar, a month-by-month task list, a seed inventory tracker, a harvest log, and succession-planting charts. Built to print, write in, and actually use all season.
Recommended for Your Garden
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Get instant, accurate soil pH readings to fine-tune your amendments.
Boost soil fertility and structure with rich, well-aged organic compost.
🥬 Vegetables to Grow in Roseau County
87 vegetables that grow well in Zone 3b with planting dates for Roseau County.
Show all 87 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Apr 9 | Jun 4 | Jun 11 | Sep 3 – Oct 8 | 80–100 |
| Amaranth | Mar 19 | Jun 4 | Jun 11 | Sep 10 – Oct 15 | 90–120 |
| Arugula | Apr 9 | May 14 | May 21 | Jun 25 – Aug 27 | 30–50 |
| Asparagus | — | — | Jun 4 | — | 730–1095 |
| Beets | — | May 14 | — | Jul 9 – Aug 6 | 50–70 |
| Belgian Endive | Apr 9 | May 14 | May 21 | Sep 10 – Sep 24 | 110–150 |
| Black Beans | — | Jun 4 | — | Sep 3 – Oct 8 | 90–120 |
| Bok Choy | Apr 9 | May 14 | May 21 | Jul 2 – Aug 6 | 40–60 |
| Broccoli | Apr 9 | May 14 | May 21 | Jul 23 – Sep 3 | 60–90 |
| Broccoli Rabe | Apr 9 | May 14 | May 21 | Jul 2 – Aug 6 | 40–60 |
| Brussels Sprouts | Apr 9 | May 14 | May 21 | Aug 20 – Sep 24 | 90–130 |
| Butternut Squash | Apr 9 | Jun 4 | Jun 11 | Sep 10 – Oct 15 | 85–110 |
| Cabbage | Apr 9 | May 14 | May 21 | Jul 23 – Sep 17 | 60–100 |
| Carrots | — | May 14 | — | Jul 16 – Aug 20 | 60–80 |
| Cauliflower | Apr 9 | May 14 | May 21 | Jul 16 – Sep 17 | 55–100 |
| Celeriac | Apr 9 | May 14 | May 21 | Sep 3 – Sep 24 | 100–120 |
| Celery | Apr 9 | May 14 | May 21 | Aug 13 – Sep 24 | 80–120 |
| Celtuce | Apr 9 | May 14 | May 21 | Jul 23 – Sep 3 | 60–90 |
| Chard | Apr 9 | May 14 | May 21 | Jul 16 – Sep 3 | 50–60 |
| Chickpeas | Apr 9 | May 14 | May 21 | Aug 13 – Sep 24 | 80–110 |
| Chicory | Apr 9 | May 14 | May 21 | Jul 23 – Sep 3 | 60–85 |
| Chinese Cabbage | Apr 9 | May 14 | May 21 | Jul 16 – Aug 13 | 50–70 |
| Collard Greens | Apr 9 | May 14 | May 21 | Jul 16 – Sep 17 | 55–75 |
| Corn | — | Jun 4 | — | Aug 6 – Oct 1 | 60–100 |
| Cress | Apr 9 | May 14 | May 21 | Jun 4 – Jun 25 | 14–21 |
| Crookneck Squash | Apr 9 | Jun 4 | Jun 11 | Jul 30 – Aug 27 | 45–60 |
| Cucumber | Apr 9 | Jun 4 | Jun 11 | Aug 6 – Oct 1 | 50–70 |
| Daikon | — | May 14 | — | Jul 9 – Aug 6 | 50–70 |
| Delicata Squash | Apr 9 | Jun 4 | Jun 11 | Sep 3 – Oct 8 | 80–100 |
| Edamame | — | Jun 4 | — | Aug 20 – Oct 1 | 75–100 |
| Endive | Apr 9 | May 14 | May 21 | Jul 9 – Aug 13 | 45–65 |
| Escarole | Apr 9 | May 14 | May 21 | Jul 16 – Aug 13 | 50–70 |
| Fava Beans | Apr 9 | May 14 | May 21 | Aug 6 – Sep 17 | 75–100 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | Jun 4 | — | Jul 30 – Sep 24 | 50–65 |
| Horseradish | — | — | Jun 4 | Oct 8 | 120–180 |
| Hubbard Squash | Apr 9 | Jun 4 | Jun 11 | Sep 24 – Oct 15 | 100–120 |
| Kabocha | Apr 9 | Jun 4 | Jun 11 | Sep 10 – Oct 8 | 85–100 |
| Kai Lan | Apr 9 | May 14 | May 21 | Jul 9 – Aug 6 | 45–60 |
| Kale | Apr 9 | May 14 | May 21 | Jul 16 – Sep 10 | 50–70 |
| Kidney Beans | — | Jun 4 | — | Sep 3 – Oct 8 | 85–110 |
| Kohlrabi | Apr 9 | May 14 | May 21 | Jul 9 – Aug 13 | 45–65 |
| Komatsuna | Apr 9 | May 14 | May 21 | Jun 25 – Jul 30 | 35–50 |
| Leeks | Apr 9 | May 14 | May 21 | Aug 20 – Sep 24 | 90–150 |
| Lentils | Apr 9 | May 14 | May 21 | Aug 13 – Sep 24 | 80–110 |
| Lettuce | Apr 9 | May 14 | May 21 | Jun 25 – Sep 3 | 30–60 |
| Lima Beans | — | Jun 4 | — | Aug 6 – Sep 17 | 60–90 |
| Mache | Apr 9 | May 14 | May 21 | Jul 2 – Aug 6 | 40–60 |
| Microgreens | Apr 9 | May 14 | May 21 | May 28 – Jun 25 | 7–21 |
| Mizuna | Apr 9 | May 14 | May 21 | Jun 25 – Jul 23 | 30–45 |
| Mustard Greens | Apr 9 | May 14 | May 21 | Jun 25 – Aug 27 | 30–50 |
| Napa Cabbage | Apr 9 | May 14 | May 21 | Jul 16 – Aug 20 | 55–75 |
| Onion | Apr 9 | May 14 | May 21 | Aug 20 – Sep 24 | 90–120 |
| Pac Choi | Apr 9 | May 14 | May 21 | Jul 2 – Jul 30 | 40–55 |
| Parsnip | — | May 14 | — | Aug 27 – Sep 17 | 100–130 |
| Patty Pan Squash | Apr 9 | Jun 4 | Jun 11 | Jul 30 – Aug 27 | 45–60 |
| Peas | Apr 9 | May 14 | May 21 | Jul 16 – Sep 10 | 55–70 |
| Peppers | Mar 5 | Jun 4 | Jun 11 | Aug 13 – Oct 15 | 60–90 |
| Pole Beans | Mar 19 | Jun 4 | Jun 11 | Aug 6 – Oct 1 | 55–70 |
| Potatoes | Mar 19 | Jun 4 | Jun 11 | Aug 20 – Oct 15 | 70–120 |
| Pumpkin | Apr 9 | Jun 4 | Jun 11 | Sep 10 – Oct 15 | 85–120 |
| Purslane | Apr 9 | May 14 | May 21 | Jul 2 – Aug 6 | 40–60 |
| Radish | — | May 14 | — | Jun 11 – Jul 2 | 22–35 |
| Rhubarb | — | — | Jun 18 | — | 365–730 |
| Romanesco | Apr 9 | May 14 | May 21 | Aug 6 – Sep 17 | 75–100 |
| Rutabaga | — | May 14 | — | Aug 6 – Sep 10 | 80–100 |
| Salsify | — | May 14 | — | Aug 27 – Sep 17 | 100–130 |
| Savoy Cabbage | Apr 9 | May 14 | May 21 | Jul 30 – Sep 24 | 70–110 |
| Scallions | Apr 9 | May 14 | May 21 | Jul 16 – Aug 13 | 50–70 |
| Scarlet Runner Beans | Mar 19 | Jun 4 | Jun 11 | Aug 13 – Sep 17 | 60–80 |
| Shiso | Mar 26 | May 28 | Jun 11 | Aug 6 – Oct 1 | 50–70 |
| Snap Peas | Mar 19 | Jun 4 | Jun 11 | Aug 6 – Oct 1 | 55–70 |
| Snow Peas | Apr 9 | May 14 | May 21 | Jul 16 – Sep 10 | 50–65 |
| Soybeans | — | Jun 4 | — | Aug 27 – Oct 8 | 80–120 |
| Spaghetti Squash | Apr 9 | Jun 4 | Jun 11 | Sep 10 – Oct 8 | 85–100 |
| Spinach | Apr 9 | May 14 | May 21 | Jun 25 – Aug 27 | 35–50 |
| Squash (Summer) | Apr 9 | Jun 4 | Jun 11 | Jul 30 – Oct 1 | 45–65 |
| Squash (Winter) | Apr 9 | Jun 4 | Jun 11 | Sep 3 – Oct 15 | 80–120 |
| Sunchoke | — | — | Jun 4 | Sep 24 – Oct 8 | 110–150 |
| Sunflower | Mar 19 | Jun 4 | Jun 11 | Aug 20 – Oct 8 | 70–100 |
| Sweet Corn | — | Jun 4 | — | Aug 6 – Sep 17 | 60–90 |
| Tatsoi | Apr 9 | May 14 | May 21 | Jun 25 – Jul 30 | 35–50 |
| Tomatoes | Mar 19 | Jun 4 | Jun 11 | Aug 13 – Oct 15 | 60–85 |
| Turnip | — | May 14 | — | Jun 25 – Jul 30 | 40–60 |
| Watercress | Apr 9 | May 14 | May 21 | Jul 2 – Aug 6 | 40–60 |
| Wax Beans | — | Jun 4 | — | Jul 30 – Sep 24 | 50–65 |
| Zucchini | Apr 9 | Jun 4 | Jun 11 | Jul 30 – Sep 24 | 45–60 |
🍓 Fruits to Grow in Roseau County
15 fruits that grow well in Zone 3b with planting dates for Roseau County.
Show all 15 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Jun 18 | Sep 17 – Oct 22 | 90–180 |
| Aronia | — | — | Jun 18 | — | 730–1095 |
| Blueberries | — | — | Jun 18 | — | 730–1095 |
| Cranberries | — | — | Jun 18 | — | 730–1095 |
| Currants | — | — | Jun 18 | — | 730–1095 |
| Elderberries | — | — | Jun 18 | — | 730–1095 |
| Goji Berries | — | — | Jun 18 | — | 730–1095 |
| Gooseberries | — | — | Jun 18 | — | 730–1095 |
| Hardy Kiwi | — | — | Jun 18 | — | 1095–1825 |
| Haskaps | — | — | Jun 18 | — | 730–1095 |
| Jostaberry | — | — | Jun 18 | — | 730–1095 |
| Lingonberries | — | — | Jun 18 | — | 730–1095 |
| Raspberries | — | — | Jun 18 | — | 365–730 |
| Serviceberries | — | — | Jun 18 | — | 730–1095 |
| Strawberries | — | — | Jun 18 | Sep 17 – Oct 22 | 90–365 |
🌿 Herbs to Grow in Roseau County
22 herbs that grow well in Zone 3b with planting dates for Roseau County.
Show all 22 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Apr 9 | May 14 | May 14 | — | 365–730 |
| Bee Balm | — | — | May 28 | Aug 27 – Oct 1 | 90–120 |
| Borage | Apr 9 | May 14 | May 14 | Jul 9 – Aug 27 | 50–60 |
| Caraway | Apr 9 | May 14 | May 14 | — | 365–450 |
| Catnip | — | — | May 28 | Jul 30 – Oct 1 | 60–80 |
| Chamomile | Apr 9 | May 14 | May 14 | Jul 16 – Sep 17 | 60–90 |
| Chervil | Apr 9 | May 14 | May 14 | Jun 25 – Aug 27 | 40–60 |
| Chives | — | — | May 28 | Jul 30 – Oct 1 | 60–90 |
| Cilantro | Apr 9 | May 14 | May 14 | Jun 25 – Aug 27 | 40–60 |
| Comfrey | — | — | May 28 | Jul 30 – Oct 1 | 60–90 |
| Dill | Apr 9 | May 14 | May 14 | Jun 25 – Aug 27 | 40–60 |
| Echinacea | — | — | May 28 | Oct 1 | 120–180 |
| Garlic Chives | — | — | May 28 | Jul 30 – Oct 1 | 60–90 |
| Horehound | — | — | May 28 | Aug 13 – Oct 1 | 75–90 |
| Hyssop | — | — | May 28 | Aug 6 – Oct 1 | 70–90 |
| Lemon Balm | — | — | May 28 | Jul 30 – Sep 17 | 60–70 |
| Lovage | — | — | May 28 | Aug 6 – Oct 1 | 70–90 |
| Mint | — | — | May 28 | Jul 30 – Oct 1 | 60–90 |
| Parsley | Apr 9 | May 14 | May 14 | Jul 16 – Sep 17 | 60–80 |
| Sorrel | Apr 9 | May 14 | May 14 | Jun 25 – Aug 27 | 40–60 |
| Valerian | — | — | May 28 | Oct 1 | 120–180 |
| Yarrow | — | — | May 28 | Aug 27 – Oct 1 | 90–120 |
Monthly Planting Guide for Roseau County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Roseau County.
Frequently Asked Questions
What planting zone is Roseau County, MN?
Roseau County is in USDA Hardiness Zone 3b. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.
When is the last frost in Roseau County, MN?
Based on 31 years of NOAA weather station data, the median last spring frost in Roseau County falls around May 21. In 8 out of 10 years, last frost lands between April 28 and June 4 — a 36-day window of variability. Use June 4 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Roseau County, MN?
The median first fall frost in Roseau County arrives around September 22. In cold years it can arrive as early as September 7; in mild years as late as October 8. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Roseau County?
Roseau County has a frost-free growing season of approximately 124 days. Focus on short-season varieties and start warm-season crops indoors 6–8 weeks before last frost. Climate records show the growing season is trending shorter by about 1.91 days per decade.
What is the soil like in Roseau County for gardening?
Roseau County has predominantly Silt Loam soil with a pH range of 5.9–7.2 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Roseau County?
Roseau County has commercial agriculture that includes Soybeans, Corn, Hay, Dairy, Sweet Corn. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Roseau County a good location for home gardening?
Roseau County scores 61/100 (Good) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. Conditions here are moderate — most common crops grow well with standard timing and care.
Your Roseau County Garden Planner — Free
A 24-page printable planner built for Roseau County (Zone 3b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.
The Gardener's Encyclopedia to Companion Planting
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
- Full seed-starting + planting schedule with timing and spacing
- Bonus: square-foot gardening guide + printable seasonal planners
Seed Saving & Storage Guide
Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.
- 200 plants, step-by-step: life cycle, pollination type, isolation
- Exact temperature + humidity ranges that keep seeds viable
- Bonus: searchable Google Sheets tracker + custom GPT assistant
Composting Guide for Homesteaders
Turn kitchen scraps and yard waste into compost that actually feeds the garden — instead of a pile that smells, attracts pests, and never breaks down.
- 14 sections on composting methods, soil science, and troubleshooting
- The 7-step hot-compost system from start to finish
- Bonus tools: troubleshooting chart, safety guide, monitoring log