When to Plant Cauliflower in Mercer County, ND
May to-do list for Mercer County, North Dakota
May is a pivotal month for Mercer County, North Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Transplant cauliflower outside
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Direct-sow cauliflower
Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.
June prep starts now
- Starting indoors: cauliflower
Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.
Mercer County, North Dakota is in USDA Zone 4a. The average last spring frost is May 16 and the first fall frost is September 24, giving you a growing season of approximately 131 days.
At an elevation of 1,118 feet, Mercer County receives approximately 23 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Cauliflower to ensure they mature before fall.
Mercer County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.5
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Mercer County
How your county's soil matches Cauliflower's growing requirements.
Soil pH
Your soil pH (6.2–7.5) overlaps with Cauliflower's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Mercer County is excellent for Cauliflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Cauliflower.
How to Plant Cauliflower
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Cauliflower
Sow every 6.3 weeks. Last sowing by Jun 16 to harvest before frost.
For a dedicated fall crop, sow by Jul 02.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Cauliflower
Cauliflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Cauliflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Jun | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jul | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Aug | 4.3" | 2.3" | 2" | 💧 Light watering |
| Sep | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.8" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Mercer County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cauliflower Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Cauliflower Planting Timeline — Mercer County, ND
Cauliflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 16 | May 16 – May 30 |
| Direct Sow | May 9 | May 9 – May 30 |
| Harvest | July 11 | Jul 11 – Sep 12 |
| Fall Sowing | July 2 | Jul 2 – Jul 16 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
55–100 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 4a
📆 Growing Season
131 days in Mercer County
Growing Tips for Cauliflower in Mercer County
Direct sow Cauliflower outdoors after May 16 in Mercer County when soil has warmed and frost danger has passed.
Common pests for Cauliflower in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Mercer County receives only 23" of rain annually. Cauliflower needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Cauliflower in Other Locations
Frequently Asked Questions
When should I plant Cauliflower in Mercer County, ND?
Mercer County is in Zone 4a with an average last frost of May 16. Plan your Cauliflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mercer County, ND?
Mercer County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 16 and first fall frost is September 24.
Your Mercer County Garden Planner — Free
A 24-page printable planner built for Mercer 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.