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Cass County, MN — Planting Guide

Cass County, Minnesota Zone 4a June

Cass County, Minnesota gardeners: here's your June plan

Your Cass County, Minnesota garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost May 12
Avg. first frost September 28
Soil temp (4") 61°F
Watering Low
Pest pressure Moderate
Daylight 15.7 hrs
  1. Get basil, cucumber, and peppers 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.

  2. Indoor seed-starting week for cucumber, kale, and lettuce

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  3. Start harvesting lettuce, radish, and arugula

    If you can't use it all right away, check the food-preservation section of your planner.

A few tasks this June that'll pay off in July
  • Starting indoors: basil, peppers, and pole beans
  • First harvests: basil, carrots, and cucumber
  • Fall sowing: carrots, kale, and lettuce

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Cass County is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 28, giving you a growing season of approximately 139 days.

At an elevation of 938 ft, Cass County receives approximately 32.4 in of rainfall annually. Summer highs average 80°F with winter lows around -9°F. The predominant soil type is Silt Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 30 days year to year — ranging from April 27 in warm years to May 27 in cold years. The growing season is trending longer by about 0.83 days per decade. Cass County scores 72/100 (Good) on the Microclimate Index.

🌡️ Zone

4a (-30°F to -25°F min)

❄️ Last Frost

May 12

🍂 First Frost

September 28

📅 Growing Season

139 days

⛰️ Elevation

938 ft

🌧️ Annual Rainfall

32.4 in

Cass County, MN Short season
139 days
Last Spring Frost May 12
139 growing days
First Fall Frost September 28

Monthly Watering Calendar for Cass County

When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.

Why it matters: Over-watering kills more plants than under-watering. Cass County's 32" annual rainfall changes the gardening playbook — humid-region gardeners often water by the calendar when they should water by the soil moisture.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 1.3" Feb 1.4" Mar 2.1" Apr 3" +0.8" May 3.5" +0.4" Jun 3.9" +0.5" Jul 3.8" +0.8" Aug 3.5" +1.1" Sep 3.2" Oct 2.5" Nov 2.2" Dec 2"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 1.3 in 7 days None
Feb 1.4 in 7 days None
Mar 2.1 in 8 days None
Apr 3 in 9 days None
May 3.5 in 11 days 0.8 in Moderate
Jun 3.9 in 9 days 0.4 in Low
Jul 3.8 in 9 days 0.5 in Low
Aug 3.5 in 7 days 0.8 in Moderate
Sep 3.2 in 9 days 1.1 in Moderate
Oct 2.5 in 8 days None
Nov 2.2 in 7 days None
Dec 2 in 6 days None

Annual total: 32.4 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.

Cass County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.9

Drainage

Well Drained

Frost Risk Probability

Based on 31 years of NOAA weather station data from 3 stations

Too early frost risk Safe to Plant May 12 → Sep 28 139 frost-free days Protect crops frost returns Apr May Jun Jul Aug Sep Oct Nov Safe: May 27 Protect by: Oct 11

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) May 27 Oct 11 137 days
Cautious May 18 Oct 4 139 days
Average year May 12 Sep 28 139 days
Optimistic May 8 Sep 23 138 days
Aggressive (risky) Apr 27 Sep 11 137 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±30 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.

🌱
Is the growing season changing?

Slightly — seasons are trending a bit longer (0.8 days/decade). Historical frost dates are still reliable for planning.

Gardening Difficulty Score

72 Good
Frost Timing Risk
10.0/10
Drought Risk
3.5/10
Soil Difficulty
0.0/10
Altitude Challenge
0.0/10
Climate Shift
3.3/10
Rainfall Challenge
0.0/10

Cass County offers good growing conditions. A little planning around frost dates goes a long way.

Zone 4a Frost Countdown
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Last Frost: May 12 First Frost: Sep 28

Local Gardening Help in Cass 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 Cass County's climate and soil.

County Extension Office

Cass 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.

Find Master Gardeners in MN →

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.

Request a Soil Test →

Services Available in Cass County

Soil testing Cold-climate gardening Pest diagnostics
Finding local nurseries & garden centers in Cass County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Cass 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 Cass County MN" or "garden center Cass 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 Cass County MN" or check your extension office and local parks department. Facebook groups like "Cass 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.

Show 6 more succession options
After Sweet Corn (harvest ends Aug 25) 34 days until frost
After Alliums (harvest ends Jul 14) 76 days until frost
After Patty Pan Squash (harvest ends Aug 18) 41 days until frost
After Pansy (harvest ends Aug 25) 34 days until frost
After Cilantro (harvest ends Aug 18) 41 days until frost
After Crookneck Squash (harvest ends Aug 18) 41 days until frost

Sunlight & Day Length in Cass County

Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.

Why it matters: Day length triggers flowering in many crops. Some need short days (sweet potatoes), some long (most flowers), and some are day-neutral (most modern tomatoes). Cass County's latitude determines which varieties fit your beds.

Longest Day

15.7 hours

Summer solstice daylight

Shortest Day

8.3 hours

Winter solstice daylight

Peak Sun Hours

9.8 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.

14hr 12hr 2h 6h 10h 13h 17h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Daylight hours (sunrise to sunset) Peak sun hours (direct sunlight after cloud cover) ▪ Gold zone = long day (14+ hr) ▪ Blue zone = short day (<12 hr)

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
MonthDaylight HoursPeak Sun HoursDay Length
January 8.7 hr 3.4 hr Short day
February 10 hr 4.3 hr Short day
March 11.6 hr 5.5 hr Short day
April 13.4 hr 7 hr Neutral
May 14.9 hr 8.5 hr Long day
June 15.7 hr 9.7 hr Long day
July 15.3 hr 9.8 hr Long day
August 14 hr 8.4 hr Long day
September 12.3 hr 7 hr Neutral
October 10.6 hr 5.6 hr Short day
November 9.1 hr 3.6 hr Short day
December 8.3 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 in Cass County

Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.

Quick context: Soil temperature predicts plant emergence better than calendar dates. Cass County's spring soil warm-up curve tells you which weeks are safe for direct-sow beans, cucumbers, squash, and corn.

Plant Warm Crops When

Soil reaches 60°F+

Soil warm enough from Jun through Sep.

Best Month to Compost

Jul

Microbial activity peaks when soil is warm.

Active Composting

4 months

Short season — insulate pile or use indoor vermicomposting.

60°F 70°F 20° 40° 60° 80° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
4" depth 8" depth - - - 60°F (corn, beans) - - - 70°F (tomatoes, peppers)
View detailed monthly data
MonthSoil 4" DeepSoil 8" DeepCompost ActivityTime to Finish
Jan 7°F 17°F ❄️ Dormant ~36 weeks
Feb 8°F 16°F ❄️ Dormant ~36 weeks
Mar 19°F 22°F ❄️ Dormant ~36 weeks
Apr 35°F 33°F ❄️ Dormant ~36 weeks
May 49°F 46°F 🐢 Slow ~24 weeks
Jun 61°F 55°F ♻️ Active ~14 weeks
Jul 69°F 63°F 🔥 Peak ~8 weeks
Aug 70°F 63°F 🔥 Peak ~8 weeks
Sep 62°F 61°F ♻️ Active ~14 weeks
Oct 46°F 50°F 🐢 Slow ~24 weeks
Nov 32°F 37°F ❄️ Dormant ~36 weeks
Dec 18°F 24°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 Cass County

Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.

Quick context: Pest pressure is a function of climate, not effort. Cass County's baseline tells you how much vigilance is normal. A bad pest year in low-pressure region = a normal year in high-pressure region.

Insect Pest Pressure

4.6 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

1.9 / 10

Low disease risk — dry conditions reduce fungal problems.

Seasonal Risk

Spring Low
Summer Moderate
Fall Low
Winter Low
View 3 common pests in your area
PestRisk LevelPeak Months
Aphids Low 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 Cass County

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with planting dates calibrated for your area.

What this means for you: Cover crops fix nitrogen by hosting bacteria that pull it from the air. A vigorous legume cover crop can deliver 50-150 lbs/acre of nitrogen — meaningful for the next vegetable season.

Spring Cover Crops (2 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat May 21 Jul 27 Rapid growth, attracts pollinators, suppresses weeds
White clover Apr 15 Jul 20 ✓ 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 2 Sep 7 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 27 Apr 21 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jun 29 Apr 21 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jun 20 Apr 21 Erosion control, weed suppression, good biomass

Wind & Microclimate in Cass County

Why this matters: A 10 mph wind doesn't feel like much, but it triples leaf transpiration vs. still air. Cass County's 8.7 mph average means most days are gentle on plants, but consider how a 20+ mph spring gust would affect a flat of seedlings hardened off too quickly.

Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.

Seasonal Wind Speed

Spring: 12 mph   Summer: 9 mph

Fall: 10 mph   Winter: 12 mph

Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.

Windbreak Benefit

4.8/10

Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.

Frost Pocket Risk

Low

Relatively flat terrain (181 ft range). Frost pocket risk is minimal — garden placement is flexible.

Rainwater Harvesting in Cass County

How much water you can collect, when to collect it, and what size system you need for your garden.

For new gardeners: A single rain barrel under a downspout catches 50 gallons in a 0.5" storm. Cass County's 32" annual rainfall means even modest harvesting systems quickly amortize their cost in water savings.

Annual Collection

16,148 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 32.4 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 16,148 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 Cass County

Soil Type

Silt Loam

Soil pH 5.9–6.9 · Well Drained drainage

Native soil is well-suited to most vegetables and herbs with regular compost additions.

Watering Needs

Drought stress: 3.5/10

Low-to-moderate drought stress. Plan to water 1–2 times per week during peak summer. (32.4 in. annual rainfall)

Season Tips

139-day frost-free season

Start warm-season crops indoors and focus on short-season varieties. Cold frames extend your season by 3–4 weeks in fall.

Your Free Printable Garden Planner

Plan every bed, every planting, every harvest — in one place. This 22-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.

Instant PDF download. No spam, unsubscribe any time.

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Recommended for Your Garden

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

📏
Digital pH Meter $10-20

Get instant, accurate soil pH readings to fine-tune your amendments.

🍂
Organic Compost $8-30

Boost soil fertility and structure with rich, well-aged organic compost.

🥬 Vegetables to Grow in Cass County

95 vegetables that grow well in Zone 4a with planting dates for Cass County.

Show all 95 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Acorn Squash Mar 31 May 26 Jun 2 Aug 25 – Sep 29 80–100
Amaranth Mar 10 May 26 Jun 2 Sep 1 – Oct 20 90–120
Arugula Mar 31 May 5 May 12 Jul 6 Jun 16 – Aug 18 30–50
Asparagus May 26 730–1095
Beets May 5 Jul 6 Jun 30 – Jul 28 50–70
Belgian Endive Mar 31 May 5 May 12 Jul 6 Sep 1 – Oct 6 110–150
Black Beans May 26 Aug 25 – Oct 13 90–120
Bok Choy Mar 31 May 5 May 12 Jul 6 Jun 23 – Jul 28 40–60
Broccoli Mar 31 May 5 May 12 Jul 6 Jul 14 – Aug 25 60–90
Broccoli Rabe Mar 31 May 5 May 12 Jul 6 Jun 23 – Jul 28 40–60
Brussels Sprouts Mar 31 May 5 May 12 Jul 6 Aug 11 – Oct 6 90–130
Butternut Squash Mar 31 May 26 Jun 2 Sep 1 – Oct 6 85–110
Cabbage Mar 31 May 5 May 12 Jul 6 Jul 14 – Sep 8 60–100
Carrots May 5 Jul 6 Jul 7 – Aug 11 60–80
Cauliflower Mar 31 May 5 May 12 Jul 6 Jul 7 – Sep 8 55–100
Celeriac Mar 31 May 5 May 12 Jul 6 Aug 25 – Sep 29 100–120
Celery Mar 31 May 5 May 12 Jul 6 Aug 4 – Sep 29 80–120
Celtuce Mar 31 May 5 May 12 Jul 6 Jul 14 – Aug 25 60–90
Chard Mar 31 May 5 May 12 Jul 6 Jul 7 – Aug 25 50–60
Chickpeas Mar 31 May 5 May 12 Jul 6 Aug 4 – Sep 15 80–110
Chicory Mar 31 May 5 May 12 Jul 6 Jul 14 – Aug 25 60–85
Chinese Cabbage Mar 31 May 5 May 12 Jul 6 Jul 7 – Aug 4 50–70
Christmas Lima Beans Mar 10 May 26 Jun 2 Aug 25 – Sep 29 80–100
Collard Greens Mar 31 May 5 May 12 Jul 6 Jul 7 – Sep 8 55–75
Corn May 26 Jul 28 – Sep 22 60–100
Cress Mar 31 May 5 May 12 Jul 6 May 26 – Jun 16 14–21
Crookneck Squash Mar 31 May 26 Jun 2 Jul 21 – Aug 18 45–60
Crosne May 5 Jul 6 Oct 6 – Sep 29 150–200
Cucumber Mar 31 May 26 Jun 2 Jul 28 – Sep 22 50–70
Daikon May 5 Jul 6 Jun 30 – Jul 28 50–70
Delicata Squash Mar 31 May 26 Jun 2 Aug 25 – Sep 29 80–100
Edamame May 26 Aug 11 – Sep 22 75–100
Endive Mar 31 May 5 May 12 Jul 6 Jun 30 – Aug 4 45–65
Escarole Mar 31 May 5 May 12 Jul 6 Jul 7 – Aug 4 50–70
Fava Beans Mar 31 May 5 May 12 Jul 6 Jul 28 – Sep 8 75–100
Fennel Mar 10 May 26 Jun 2 Aug 4 – Sep 15 60–90
Garlic Aug 17 Nov 16 – Jan 11 90–240
Green Beans May 26 Jul 21 – Sep 15 50–65
Horseradish May 26 Sep 29 – Oct 20 120–180
Hubbard Squash Mar 31 May 26 Jun 2 Sep 15 – Oct 20 100–120
Kabocha Mar 31 May 26 Jun 2 Sep 1 – Sep 29 85–100
Kai Lan Mar 31 May 5 May 12 Jul 6 Jun 30 – Jul 28 45–60
Kale Mar 31 May 5 May 12 Jul 6 Jul 7 – Sep 1 50–70
Kidney Beans May 26 Aug 25 – Sep 29 85–110
Kohlrabi Mar 31 May 5 May 12 Jul 6 Jun 30 – Aug 4 45–65
Komatsuna Mar 31 May 5 May 12 Jul 6 Jun 16 – Jul 21 35–50
Leeks Mar 31 May 5 May 12 Jul 6 Aug 11 – Oct 6 90–150
Lentils Mar 31 May 5 May 12 Jul 6 Aug 4 – Sep 15 80–110
Lettuce Mar 31 May 5 May 12 Jul 6 Jun 16 – Aug 25 30–60
Lima Beans May 26 Jul 28 – Sep 8 60–90
Mache Mar 31 May 5 May 12 Jul 6 Jun 23 – Jul 28 40–60
Melon Mar 31 May 26 Jun 2 Aug 11 – Sep 29 70–100
Microgreens Mar 31 May 5 May 12 Jul 6 May 19 – Jun 16 7–21
Mitsuba Mar 31 May 5 May 5 Jul 6 Jun 30 – Aug 25 50–70
Mizuna Mar 31 May 5 May 12 Jul 6 Jun 16 – Jul 14 30–45
Mustard Greens Mar 31 May 5 May 12 Jul 6 Jun 16 – Aug 18 30–50
Napa Cabbage Mar 31 May 5 May 12 Jul 6 Jul 7 – Aug 11 55–75
Onion Mar 31 May 5 May 12 Jul 6 Aug 11 – Sep 29 90–120
Pac Choi Mar 31 May 5 May 12 Jul 6 Jun 23 – Jul 21 40–55
Parsnip May 5 Jul 6 Aug 18 – Sep 29 100–130
Patty Pan Squash Mar 31 May 26 Jun 2 Jul 21 – Aug 18 45–60
Peas Mar 31 May 5 May 12 Jul 6 Jul 7 – Sep 1 55–70
Peppers Feb 24 May 26 Jun 2 Aug 4 – Oct 13 60–90
Pole Beans Mar 10 May 26 Jun 2 Jul 28 – Sep 22 55–70
Potatoes Mar 10 May 26 Jun 2 Aug 11 – Oct 20 70–120
Pumpkin Mar 31 May 26 Jun 2 Sep 1 – Oct 20 85–120
Purslane Mar 31 May 5 May 12 Jul 6 Jun 23 – Jul 28 40–60
Radicchio Mar 31 May 5 May 12 Jul 6 Jul 14 – Aug 18 60–80
Radish May 5 Jul 6 Jun 2 – Jun 23 22–35
Rhubarb Jun 9 365–730
Romanesco Mar 31 May 5 May 12 Jul 6 Jul 28 – Sep 8 75–100
Rutabaga May 5 Jul 6 Jul 28 – Sep 1 80–100
Salsify May 5 Jul 6 Aug 18 – Sep 29 100–130
Savoy Cabbage Mar 31 May 5 May 12 Jul 6 Jul 21 – Sep 15 70–110
Scallions Mar 31 May 5 May 12 Jul 6 Jul 7 – Aug 4 50–70
Scarlet Runner Beans Mar 10 May 26 Jun 2 Aug 4 – Sep 8 60–80
Shallot Mar 31 May 5 May 12 Jul 6 Aug 11 – Sep 29 90–120
Shiso Mar 17 May 19 Jun 2 Jul 28 – Sep 22 50–70
Snap Peas Mar 10 May 26 Jun 2 Jul 28 – Sep 22 55–70
Snow Peas Mar 31 May 5 May 12 Jul 6 Jul 7 – Sep 1 50–65
Soybeans May 26 Aug 18 – Oct 13 80–120
Spaghetti Squash Mar 31 May 26 Jun 2 Sep 1 – Sep 29 85–100
Spinach Mar 31 May 5 May 12 Jul 6 Jun 16 – Aug 18 35–50
Squash (Summer) Mar 31 May 26 Jun 2 Jul 21 – Sep 22 45–65
Squash (Winter) Mar 31 May 26 Jun 2 Aug 25 – Oct 20 80–120
Sunchoke May 26 Sep 15 – Oct 20 110–150
Sweet Corn May 26 Jul 28 – Sep 8 60–90
Tatsoi Mar 31 May 5 May 12 Jul 6 Jun 16 – Jul 21 35–50
Tomatillo Mar 10 May 26 Jun 2 Aug 4 – Oct 13 60–85
Tomatoes Mar 10 May 26 Jun 2 Aug 4 – Oct 13 60–85
Turnip May 5 Jul 6 Jun 16 – Jul 21 40–60
Watercress Mar 31 May 5 May 12 Jul 6 Jun 23 – Jul 28 40–60
Watermelon Mar 31 May 26 Jun 2 Aug 11 – Sep 29 70–100
Wax Beans May 26 Jul 21 – Sep 15 50–65
Zucchini Mar 31 May 26 Jun 2 Jul 21 – Sep 15 45–60

🍓 Fruits to Grow in Cass County

22 fruits that grow well in Zone 4a with planting dates for Cass County.

Show all 22 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Alpine Strawberries Jun 9 Sep 8 – Nov 3 90–180
Aronia Jun 9 730–1095
Blueberries Jun 9 730–1095
Cantaloupe Jun 9 Aug 18 – Sep 22 70–90
Cranberries Jun 9 730–1095
Currants Jun 9 730–1095
Elderberries Jun 9 730–1095
Goji Berries Jun 9 730–1095
Gooseberries Jun 9 730–1095
Grapes Jun 9 730–1095
Ground Cherry Jun 9 Aug 18 – Oct 13 65–80
Hardy Kiwi Jun 9 1095–1825
Haskaps Jun 9 730–1095
Honeydew Jun 9 Sep 1 – Oct 13 80–110
Jostaberry Jun 9 730–1095
Lingonberries Jun 9 730–1095
Medlar Jun 9 1095–1825
Mulberries Jun 9 730–1825
Persimmon Jun 9 1095–2555
Raspberries Jun 9 365–730
Serviceberries Jun 9 730–1095
Strawberries Jun 9 Sep 8 – Nov 3 90–365

🌿 Herbs to Grow in Cass County

30 herbs that grow well in Zone 4a with planting dates for Cass County.

Show all 30 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Angelica Mar 31 May 5 May 5 Jul 6 365–730
Anise Mar 31 May 5 May 5 Jul 6 Aug 4 – Sep 29 90–120
Basil Mar 17 May 19 Jun 2 Jul 28 – Sep 29 50–75
Bee Balm May 19 Aug 18 – Oct 13 90–120
Borage Mar 31 May 5 May 5 Jul 6 Jun 30 – Aug 18 50–60
Caraway Mar 31 May 5 May 5 Jul 6 365–450
Catnip May 19 Jul 21 – Sep 22 60–80
Chamomile Mar 31 May 5 May 5 Jul 6 Jul 7 – Sep 15 60–90
Chervil Mar 31 May 5 May 5 Jul 6 Jun 16 – Aug 18 40–60
Chives May 19 Jul 21 – Sep 29 60–90
Cilantro Mar 31 May 5 May 5 Jul 6 Jun 16 – Aug 18 40–60
Comfrey May 19 Jul 21 – Sep 29 60–90
Dill Mar 31 May 5 May 5 Jul 6 Jun 16 – Aug 18 40–60
Fennel (herb) Mar 31 May 5 May 5 Jul 6 Jul 7 – Sep 15 60–90
Garlic Chives May 19 Jul 21 – Sep 29 60–90
Horehound May 19 Aug 4 – Sep 29 75–90
Hyssop May 19 Jul 28 – Sep 29 70–90
Lemon Balm May 19 Jul 21 – Sep 8 60–70
Lovage May 19 Jul 28 – Sep 29 70–90
Mint May 19 Jul 21 – Sep 29 60–90
Oregano May 19 Jul 21 – Sep 29 60–90
Parsley Mar 31 May 5 May 5 Jul 6 Jul 7 – Sep 8 60–80
Rue May 19 Jul 28 – Sep 29 70–90
Sage May 19 Aug 4 – Sep 29 75–90
Savory May 19 Jul 14 – Sep 8 50–70
Sorrel Mar 31 May 5 May 5 Jul 6 Jun 16 – Aug 18 40–60
Tarragon May 19 Jul 21 – Sep 29 60–90
Thai Basil Mar 17 May 19 Jun 2 Jul 28 – Sep 29 50–75
Thyme May 19 Jul 28 – Sep 29 70–90
Valerian May 19 Sep 22 – Oct 13 120–180

🌸 Flowers to Grow in Cass County

49 flowers that grow well in Zone 4a with planting dates for Cass County.

Show all 49 flowers with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Bloom Days to Maturity
Ageratum Mar 17 May 19 May 19 Jul 14 – Sep 22 60–75
Alliums Aug 17 Sep 28 – Oct 19 28–42
Astilbe Mar 3 May 26 Aug 18 – Oct 13 70–100
Bachelor's Button Mar 24 Apr 28 May 12 Jul 14 – Sep 15 60–90
Begonias Feb 24 May 26 Aug 4 – Oct 6 70–90
Black-eyed Susan Mar 3 May 12 May 26 Aug 18 – Oct 27 60–80
Bleeding Hearts Mar 3 May 26 Jul 21 – Sep 1 60–90
Calendula Mar 24 Apr 28 May 12 Jun 30 – Sep 15 50–70
Celosia Mar 31 May 26 May 26 Jul 28 – Oct 13 60–90
Columbine Mar 3 May 26 May 26 Jul 21 – Sep 1 70–100
Coreopsis Mar 3 May 19 May 26 Aug 11 – Oct 27 60–80
Cosmos Apr 14 May 19 May 19 Jul 28 – Oct 13 60–90
Crocus Aug 17 Jun 22 – Jul 13 10–20
Daffodils Aug 17 Jun 29 – Jul 20 20–40
Dahlias Apr 14 May 26 May 26 Aug 25 – Oct 27 70–120
Daylily Mar 3 May 26 Aug 25 – Oct 27 60–90
Dianthus Mar 10 Apr 21 May 5 Jun 23 – Aug 25 60–80
Echinacea (Purple Coneflower) Mar 3 May 26 May 26 Aug 25 – Oct 27 70–90
Foxglove Mar 3 May 26 May 26 Jul 21 – Sep 1 80–120
Gaillardia (Blanket Flower) Mar 17 May 26 May 26 Aug 4 – Nov 3 70–100
Geraniums Feb 24 May 26 Aug 4 – Oct 6 70–100
Gladiolus May 19 May 19 Aug 18 – Oct 20 70–100
Hostas Feb 24 May 26 Aug 25 – Oct 27 60–90
Hyacinths Aug 17 Jul 20 – Aug 10 14–28
Hydrangeas Feb 24 May 26 Aug 18 – Oct 13 90–150
Impatiens Mar 10 May 26 Aug 11 – Oct 6 60–75
Irises Division May 26 Jul 21 – Aug 18 60–100
Larkspur Apr 7 Jun 16 – Jul 28 60–90
Lilies Division May 26 Aug 18 – Oct 20 70–120
Lobelia Mar 3 May 12 Jul 7 – Sep 1 70–80
Lupine Mar 3 May 26 May 26 Jul 21 – Sep 1 75–100
Marigolds Mar 31 May 26 May 26 Jul 21 – Oct 6 50–70
Nasturtium Apr 14 May 26 May 26 Jul 21 – Oct 6 55–65
Pansy Feb 24 May 12 Jul 7 – Aug 25 70–90
Peonies Division May 26 Aug 4 – Sep 8 90–120
Petunia Mar 10 May 26 Aug 11 – Oct 13 70–90
Phlox Mar 3 May 26 May 26 Aug 18 – Oct 20 80–110
Portulaca Mar 31 May 26 May 26 Jul 14 – Sep 22 50–70
Roses Feb 24 May 26 Aug 18 – Oct 27 90–180
Salvia Mar 3 May 26 Aug 4 – Oct 6 70–90
Sedum (Stonecrop) Mar 3 May 26 Sep 29 – Nov 17 60–90
Snapdragon Feb 24 May 12 Jul 21 – Sep 15 70–100
Sunflower Apr 21 May 26 May 26 Aug 18 – Oct 13 70–100
Sweet Alyssum Mar 17 May 5 May 12 Jun 23 – Aug 25 45–60
Sweet Pea Mar 24 Apr 7 May 12 Aug 4 – Sep 15 65–85
Tulips Aug 17 Jul 13 – Aug 3 15–30
Vinca (Annual) Feb 24 May 26 Aug 4 – Oct 6 70–90
Yarrow Mar 3 May 12 May 26 Aug 11 – Oct 27 60–90
Zinnia Apr 14 May 26 May 26 Aug 4 – Oct 13 60–70
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Monthly Planting Guide for Cass County

Gardening Guides & Resources

Helpful guides from The Ultimate Homestead to improve your garden in Cass County.

Frequently Asked Questions

What planting zone is Cass County, MN?

Cass County is in USDA Hardiness Zone 4a. 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 Cass County, MN?

Based on 31 years of NOAA weather station data, the median last spring frost in Cass County falls around May 12. In 8 out of 10 years, last frost lands between April 27 and May 27 — a 30-day window of variability. Use May 27 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Cass County, MN?

The median first fall frost in Cass County arrives around September 28. In cold years it can arrive as early as September 11; in mild years as late as October 11. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Cass County?

Cass County has a frost-free growing season of approximately 139 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 longer by about 0.83 days per decade.

What is the soil like in Cass County for gardening?

Cass County has predominantly Silt Loam soil with a pH range of 5.9–6.9 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Cass County?

Cass County has commercial agriculture that includes Soybeans, Corn, Hay, Dairy, Oats. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.

Is Cass County a good location for home gardening?

Cass County scores 72/100 (Good) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. This is an above-average location for home gardening with relatively predictable growing conditions.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA GHCN-D daily station data (1994–2024) from 3 weather stations in or near Cass County (31 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.