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
Monthly Watering Calendar for McLean County
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
The practical takeaway: The 1-inch-per-week rule applies to most vegetable crops. McLean County averages 22" a year — divide by 52 and compare to that 1" target. Some months are above, some below; that's where the calendar earns its keep.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering 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
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 |
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.
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
McLean County presents some gardening challenges. Choose adapted varieties and plan around frost dates.
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.
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 McLean County
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
Sunlight & Day Length in McLean County
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
What this means for you: You can't change the sun. Picking the right day-length-matched varieties for McLean County matters more than any other "fix" you make — and the seed packet tells you (look for "long-day," "short-day," "day-neutral").
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.
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 | 8.6 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 in McLean County
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
Why this matters: Lettuce germinates at 35°F. Beans want 60°F. Tomatoes 65°F+. Soil temp, not air temp, is what plants feel. McLean County's monthly curve tells you when each crop actually has the conditions to take off.
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.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time 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.
For new gardeners: Warm humid regions cycle through pest generations 3-5x faster than cold dry regions. McLean County's pest score is your early-warning system: high score means commit to disease-resistant varieties and accept some crop loss to bugs.
Insect Pest Pressure
Moderate — common pests appear but manageable with monitoring.
Disease Risk
Low disease risk — dry conditions reduce fungal problems.
Seasonal Risk
View 5 common pests in your area
| Pest | Risk Level | Peak 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 planting dates calibrated for your area.
Quick context: Cover crops protect microbial life through winter and summer. Bare soil bakes; covered soil stays cooler, moister, and biologically active. The difference shows up in next year's crops.
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 in McLean County
Why it matters: Pollinators avoid windy days. McLean County's 12.9 mph average wind isn't enough to stop bees and butterflies — but plant fruiting crops (tomatoes, peppers, squash) in protected microclimates and you'll see noticeably better fruit set.
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 in McLean County
How much water you can collect, when to collect it, and what size system you need for your garden.
What this means for you: Rainwater is unchlorinated, unfluoridated, and at ambient temperature — plants actually prefer it. McLean County's 22" annual rainfall means even a small 50-gallon barrel catches enough for a few weeks of garden watering between storms.
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.
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.
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.
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.
Your McLean County Garden Planner — Free
A 22-page printable planner built for McLean County (Zone 4a). 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