When to plant Nasturtium in Mahnomen County, MN
Mahnomen County's short 137-day growing season means one Nasturtium planting between May 27 and June 17. No fall crop in Zone 4a.
When to Plant Nasturtium in Mahnomen County, MN
Nasturtium (Tropaeolum majus) is a fast-growing annual with distinctive round, lily-pad leaves and bold trumpet-shaped blooms in warm oranges, reds, and yellows. Both the flowers and leaves are edible with a peppery watercress flavor. Planted near vegetables, nasturtiums act as a sacrifice trap-crop, luring aphids away from more valuable plants. They thrive in poor, dry soil — rich conditions produce lush foliage but few flowers.
Mahnomen County, Minnesota is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 27, giving you a growing season of approximately 137 days.
At an elevation of 1,223 feet, Mahnomen County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Nasturtium to ensure they mature before fall.
Mahnomen County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7
Drainage
Well Drained
Monthly Watering Guide for Nasturtium
Nasturtium needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Nasturtium Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | — | 2.4" | 0" | ❄️ Dormant |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Mahnomen County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Nasturtium Planting Timeline — Mahnomen County, MN
Nasturtium Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 15 | Apr 15 – Apr 29 |
| Transplant Outdoors | May 27 | May 27 – Jun 10 |
| Direct Sow | May 27 | May 27 – Jun 17 |
| Bloom | July 22 | Jul 22 – Oct 7 |
Plant 0.5" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
55–65 days
🧪 Soil pH
Needs 6–8 · Your soil: N/A
🗺️ USDA Zone
Zone 4a
📆 Growing Season
137 days in Mahnomen County
Growing Tips for Mahnomen County
Direct-sow large seeds 1/2 inch deep after last frost; soak seeds overnight to speed germination (7-10 days). Nasturtiums dislike root disturbance so direct sowing is strongly preferred. Avoid fertilizing — poor soil brings the best bloom. Trailing types can cover banks and climb trellises; dwarf types suit containers. In hot climates (zones 9+) plant in fall for winter/spring bloom as plants struggle in peak summer heat.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Nasturtium in Other Locations
Frequently Asked Questions
When should I plant Nasturtium in Mahnomen County, MN?
Mahnomen County is in Zone 4a with an average last frost of May 13. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mahnomen County, MN?
Mahnomen County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 27.
When should I plant Nasturtium in Mahnomen County, MN?
In Mahnomen County, MN, plant Nasturtium after the last frost (around May 13) and before the first frost (around September 27). Best results when soil holds above 50°F.
What growing zone is Mahnomen County, MN for Nasturtium?
Mahnomen County sits in USDA Zone 4a. Nasturtium grows reliably in zones 2a through 11b, so it's a good fit here.
Can Nasturtium grow in Mahnomen County's climate?
Yes — Nasturtium grows well in Mahnomen County's temperate climate. Mahnomen County averages a 137-day frost-free season, with last frost around May 13 and first frost around September 27.
Your Mahnomen County Garden Planner — Free
A 22-page printable planner built for Mahnomen 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.