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McLean County, ND — Planting Guide

McLean County is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 30, giving you a growing season of approximately 141 days.

At an elevation of 1,071 ft, McLean County receives approximately 21.5 in of rainfall annually. Summer highs average 82°F with winter lows around 1°F. The predominant soil type is Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 24 days year to year — ranging from April 27 in warm years to May 21 in cold years. The growing season is trending longer by about 2.23 days per decade. McLean County scores 51/100 (Moderate) on the Microclimate Index.

🌡️ Zone

4a (-30°F to -25°F min)

❄️ Last Frost

May 12

🍂 First Frost

September 30

📅 Growing Season

141 days

⛰️ Elevation

1,071 ft

🌧️ Annual Rainfall

21.5 in

McLean County, ND Short season
141 days
Last Spring Frost May 12
141 growing days
First Fall Frost September 30

Monthly Watering Calendar

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

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 1.5" Feb 1.4" Mar 1.9" +1.9" Apr 2.4" +1.8" May 2.5" +2.8" Jun 1.5" +2.4" Jul 1.9" +1.9" Aug 2.4" +2.5" Sep 1.8" +2.4" Oct 1.9" Nov 1.3" Dec 1"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 1.5 in 7 days None
Feb 1.4 in 5 days None
Mar 1.9 in 8 days None
Apr 2.4 in 7 days 1.9 in High
May 2.5 in 8 days 1.8 in High
Jun 1.5 in 4 days 2.8 in High
Jul 1.9 in 6 days 2.4 in High
Aug 2.4 in 7 days 1.9 in High
Sep 1.8 in 6 days 2.5 in High
Oct 1.9 in 6 days 2.4 in High
Nov 1.3 in 6 days None
Dec 1 in 6 days None

Annual total: 21.5 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.

McLean County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

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 30 141 frost-free days Protect crops frost returns Apr May Jun Jul Aug Sep Oct Nov Safe: May 21 Protect by: Oct 12

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 21 Oct 12 144 days
Cautious May 15 Oct 4 142 days
Average year May 12 Sep 30 141 days
Optimistic May 4 Sep 22 141 days
Aggressive (risky) Apr 27 Sep 13 139 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±24 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?

Yes — growing seasons are getting longer here (about 2.2 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.

Gardening Difficulty Score

51 Moderate
Frost Timing Risk
9.2/10
Drought Risk
7.5/10
Soil Difficulty
0.0/10
Altitude Challenge
0.1/10
Climate Shift
8.9/10
Rainfall Challenge
3.4/10

McLean County presents some gardening challenges. Choose adapted varieties and plan around frost dates.

Zone 4a Frost Countdown
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Last Frost: May 12 First Frost: Sep 30

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

County Extension Office

McLean County North Dakota State University Extension Extension Office

Phone: 701-231-8944

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 ND →

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 McLean County

Soil testing Short-season gardening Pest identification
Finding local nurseries & garden centers in McLean County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to McLean 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 McLean County ND" or "garden center McLean 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 McLean County ND" or check your extension office and local parks department. Facebook groups like "McLean County Gardeners" or "North Dakota 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) 36 days until frost
After Turnip (harvest ends Jul 28) 64 days until frost
After Cilantro (harvest ends Aug 18) 43 days until frost
After Mustard Greens (harvest ends Aug 18) 43 days until frost
After Crookneck Squash (harvest ends Aug 18) 43 days until frost
After Kohlrabi (harvest ends Aug 4) 57 days until frost

Sunlight & Day Length

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

Longest Day

15.8 hours

Summer solstice daylight

Shortest Day

8.2 hours

Winter solstice daylight

Peak Sun Hours

11.5 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 3h 7h 10h 14h 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 8.6 hr 4.8 hr Short day
February 10 hr 6.1 hr Short day
March 11.6 hr 7.3 hr Short day
April 13.4 hr 8.1 hr Neutral
May 14.9 hr 9.4 hr Long day
June 15.8 hr 10.9 hr Long day
July 15.4 hr 11.5 hr Long day
August 14.1 hr 9.5 hr Long day
September 12.3 hr 8.4 hr Neutral
October 10.6 hr 7.1 hr Short day
November 9 hr 5.3 hr Short day
December 8.2 hr 4.4 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 Sep.

Best Month to Compost

Jul

Microbial activity peaks when soil is warm.

Active Composting

6 months

Solid season. Piles go dormant in winter.

60°F 70°F 23° 45° 68° 90° 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 14°F 24°F ❄️ Dormant ~36 weeks
Feb 18°F 21°F ❄️ Dormant ~36 weeks
Mar 26°F 29°F ❄️ Dormant ~36 weeks
Apr 42°F 38°F 🐢 Slow ~24 weeks
May 54°F 51°F ♻️ Active ~14 weeks
Jun 65°F 58°F ♻️ Active ~14 weeks
Jul 72°F 66°F 🔥 Peak ~8 weeks
Aug 74°F 68°F 🔥 Peak ~8 weeks
Sep 66°F 64°F 🔥 Peak ~8 weeks
Oct 52°F 56°F ♻️ Active ~14 weeks
Nov 35°F 44°F ❄️ Dormant ~36 weeks
Dec 20°F 30°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 McLean County

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

Insect Pest Pressure

5.2 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

2.5 / 10

Low disease risk — dry conditions reduce fungal problems.

Seasonal Risk

Spring Low
Summer High
Fall Low
Winter Low
View 5 common pests in your area
PestRisk LevelPeak Months
Aphids Moderate May, Jun, Jul, Aug
Cabbage worms Low Jun, Jul, Aug
Colorado potato beetle Moderate Jun, Jul
Flea beetles Moderate May, Jun, Jul
Slugs Moderate May, Jun, Jul, Aug, Sep
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 McLean 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 19 Jul 22 Rapid growth, attracts pollinators, suppresses weeds
White clover Apr 16 Aug 5 ✓ 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 12 Sep 2 Deep roots break compaction, attract pollinators and beneficial insects
Fall Cover Crops (5 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Daikon radish Aug 6 Apr 28 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jul 7 Apr 21 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 16 Apr 21 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jul 10 Apr 21 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jul 11 Apr 21 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: 17 mph   Summer: 13 mph

Fall: 14 mph   Winter: 14 mph

Prevailing wind: S. Windy area — plant a windbreak hedge on the S side of your garden.

Windbreak Benefit

9.2/10

Strongly recommended — a windbreak (fence, hedge, or row of tall crops like corn or sunflowers) will significantly improve garden yields.

Frost Pocket Risk

Low

Relatively flat terrain (301 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

10,715 gal

Per 1,000 sq ft of roof area (at 80% collection efficiency)

Recommended Setup

7 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

Mar, Apr, May, Aug

Highest rainfall months — your barrels will fill up quickly during these months.

Months to Draw From Storage

Feb, Nov, 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 21.5 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 10,715 gallons annually
  • Rainwater harvesting is fully legal in your state
  • Stock up on stored water before your dry season (Feb, Nov, Dec)
  • Use a first-flush diverter to keep roof debris out of your collection

Soil & Growing Conditions in McLean County

Soil Type

Loam

Soil pH 6.6–7.8 · Moderately Well Drained drainage

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

Watering Needs

Drought stress: 7.5/10

High drought stress. Consistent irrigation is essential — consider drip systems, heavy mulch, and drought-tolerant varieties.

Season Tips

141-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.

Free Garden Planner

Plan your entire garden season — organize planting dates, track what you're growing, and know exactly when to start seeds, transplant, and harvest.

Get My Free Planner →

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 McLean County

96 vegetables that grow well in Zone 4a with planting dates for McLean County.

Show all 96 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant 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 Jun 16 – Aug 18 30–50
Asparagus May 26 730–1095
Beets May 5 Jun 30 – Jul 28 50–70
Belgian Endive Mar 31 May 5 May 12 Sep 1 – Oct 6 110–150
Black Beans May 26 Aug 25 – Oct 13 90–120
Bok Choy Mar 31 May 5 May 12 Jun 23 – Jul 28 40–60
Broccoli Mar 31 May 5 May 12 Jul 14 – Aug 25 60–90
Broccoli Rabe Mar 31 May 5 May 12 Jun 23 – Jul 28 40–60
Brussels Sprouts Mar 31 May 5 May 12 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 14 – Sep 8 60–100
Carrots May 5 Jul 7 – Aug 11 60–80
Cauliflower Mar 31 May 5 May 12 Jul 7 – Sep 8 55–100
Celeriac Mar 31 May 5 May 12 Aug 25 – Sep 29 100–120
Celery Mar 31 May 5 May 12 Aug 4 – Sep 29 80–120
Celtuce Mar 31 May 5 May 12 Jul 14 – Aug 25 60–90
Chard Mar 31 May 5 May 12 Jul 7 – Aug 25 50–60
Chickpeas Mar 31 May 5 May 12 Aug 4 – Sep 15 80–110
Chicory Mar 31 May 5 May 12 Jul 14 – Aug 25 60–85
Chinese Cabbage Mar 31 May 5 May 12 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 7 – Sep 8 55–75
Corn May 26 Jul 28 – Sep 22 60–100
Cress Mar 31 May 5 May 12 May 26 – Jun 16 14–21
Crookneck Squash Mar 31 May 26 Jun 2 Jul 21 – Aug 18 45–60
Crosne May 5 Oct 6 – Sep 29 150–200
Cucumber Mar 31 May 26 Jun 2 Jul 28 – Sep 22 50–70
Daikon May 5 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 Jun 30 – Aug 4 45–65
Escarole Mar 31 May 5 May 12 Jul 7 – Aug 4 50–70
Fava Beans Mar 31 May 5 May 12 Jul 28 – Sep 8 75–100
Fennel Mar 10 May 26 Jun 2 Aug 4 – Sep 15 60–90
Garlic 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 Jun 30 – Jul 28 45–60
Kale Mar 31 May 5 May 12 Jul 7 – Sep 1 50–70
Kidney Beans May 26 Aug 25 – Sep 29 85–110
Kohlrabi Mar 31 May 5 May 12 Jun 30 – Aug 4 45–65
Komatsuna Mar 31 May 5 May 12 Jun 16 – Jul 21 35–50
Leeks Mar 31 May 5 May 12 Aug 11 – Oct 6 90–150
Lentils Mar 31 May 5 May 12 Aug 4 – Sep 15 80–110
Lettuce Mar 31 May 5 May 12 Jun 16 – Aug 25 30–60
Lima Beans May 26 Jul 28 – Sep 8 60–90
Mache Mar 31 May 5 May 12 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 May 19 – Jun 16 7–21
Mitsuba Mar 31 May 5 May 5 Jun 30 – Aug 25 50–70
Mizuna Mar 31 May 5 May 12 Jun 16 – Jul 14 30–45
Mustard Greens Mar 31 May 5 May 12 Jun 16 – Aug 18 30–50
Napa Cabbage Mar 31 May 5 May 12 Jul 7 – Aug 11 55–75
Onion Mar 31 May 5 May 12 Aug 11 – Sep 29 90–120
Pac Choi Mar 31 May 5 May 12 Jun 23 – Jul 21 40–55
Parsnip May 5 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 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 Jun 23 – Jul 28 40–60
Radicchio Mar 31 May 5 May 12 Jul 14 – Aug 18 60–80
Radish May 5 Jun 2 – Jun 23 22–35
Rhubarb Jun 9 365–730
Romanesco Mar 31 May 5 May 12 Jul 28 – Sep 8 75–100
Rutabaga May 5 Jul 28 – Sep 1 80–100
Salsify May 5 Aug 18 – Sep 29 100–130
Savoy Cabbage Mar 31 May 5 May 12 Jul 21 – Sep 15 70–110
Scallions Mar 31 May 5 May 12 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 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 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 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
Sunflower Mar 10 May 26 Jun 2 Aug 11 – Sep 29 70–100
Sweet Corn May 26 Jul 28 – Sep 8 60–90
Tatsoi Mar 31 May 5 May 12 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 Jun 16 – Jul 21 40–60
Watercress Mar 31 May 5 May 12 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 McLean County

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

Show all 22 fruits with planting dates
Plant Start Indoors Direct Sow Transplant 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 McLean County

32 herbs that grow well in Zone 4a with planting dates for McLean County.

Show all 32 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Angelica Mar 31 May 5 May 5 365–730
Anise Mar 31 May 5 May 5 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 Jun 30 – Aug 18 50–60
Caraway Mar 31 May 5 May 5 365–450
Catnip May 19 Jul 21 – Sep 22 60–80
Chamomile Mar 31 May 5 May 5 Jul 7 – Sep 15 60–90
Chervil Mar 31 May 5 May 5 Jun 16 – Aug 18 40–60
Chives May 19 Jul 21 – Sep 29 60–90
Cilantro Mar 31 May 5 May 5 Jun 16 – Aug 18 40–60
Comfrey May 19 Jul 21 – Sep 29 60–90
Dill Mar 31 May 5 May 5 Jun 16 – Aug 18 40–60
Echinacea May 19 Sep 22 – Oct 13 120–180
Fennel (herb) Mar 31 May 5 May 5 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 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 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
Yarrow May 19 Aug 18 – Oct 13 90–120

Monthly Planting Guide for McLean County

Gardening Guides & Resources

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

Frequently Asked Questions

What planting zone is McLean County, ND?

McLean 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 McLean County, ND?

Based on 31 years of NOAA weather station data, the median last spring frost in McLean County falls around May 12. In 8 out of 10 years, last frost lands between April 27 and May 21 — a 24-day window of variability. Use May 21 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in McLean County, ND?

The median first fall frost in McLean County arrives around September 30. In cold years it can arrive as early as September 13; in mild years as late as October 12. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in McLean County?

McLean County has a frost-free growing season of approximately 141 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 2.23 days per decade.

What is the soil like in McLean County for gardening?

McLean County has predominantly Loam soil with a pH range of 6.6–7.8 and Moderately Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in McLean County?

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

Is McLean County a good location for home gardening?

McLean County scores 51/100 (Moderate) 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.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — designed to help McLean County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Level Up Your Garden

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