When to plant Alliums in Marshall County, MN
Marshall County gardeners should plant Alliums between mid-spring and late spring in spring. With Marshall County's Zone 3b climate (last frost May 11), Alliums needs 28–42 days to mature — plant by August 21 for a full harvest. A second sowing from August 21 to September 4 extends the harvest into fall.
When to Plant Alliums in Marshall County, MN
What to do in June
We've pulled the most time-sensitive tasks for Marshall County, Minnesota this June and put them front and centre. Tackle them in order.
Ornamental alliums (Allium spp.) bridge the gap between spring and summer with their striking globe-shaped flower heads in shades of purple, violet, white, and pink. Blooming after tulips have faded, they extend the spring display well into early summer. 'Gladiator', 'Globemaster', and 'Purple Sensation' produce softball-sized heads on 18–36 inch stems, while smaller species create charming accents at border fronts. Deer and rodents shun them completely due to the characteristic onion scent. Dried seed heads provide architectural interest into fall.
Marshall County, Minnesota is in USDA Zone 3b. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.
At an elevation of 1,303 feet, Marshall County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Alliums to ensure they mature before fall.
Marshall County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.3
Drainage
Well Drained
Alliums 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 Marshall County
How your county's soil matches Alliums's growing requirements.
Soil pH
Your soil pH (5.8–7.3) is within Alliums's preferred range (5.5–7.5).
Soil Texture
The silt loam soil in Marshall County is excellent for Alliums — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Alliums will thrive.
How to Plant Alliums
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Succession Planting Alliums
Sow every 3.1 weeks. Last sowing by Aug 21 to harvest before frost.
For a dedicated fall crop, sow by Aug 21.
Alliums Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Alliums
Alliums needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Alliums Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | — | 3.2" | 0" | ❄️ Dormant |
| May | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Marshall County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Alliums 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.
Alliums Planting Timeline — Marshall County, MN
Alliums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 2 | Oct 2 – Oct 30 |
| Fall Sowing | August 21 | Aug 21 – Sep 4 |
Plant 5" deep · 7" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
28–42 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 3b
📆 Growing Season
144 days in Marshall County
Growing Tips for Alliums in Marshall County
Direct sow Alliums outdoors after May 11 in Marshall County when soil has warmed and frost danger has passed.
Your generous 144.0-day season in Marshall County allows multiple plantings of Alliums. Sow every 14.0 days for continuous harvest.
Common pests for Alliums in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant bulbs in fall, 3–4 times as deep as the bulb diameter (typically 4–6 inches for large types, 3 inches for small species). Space 6–8 inches apart for standard cultivars. Foliage often looks untidy as it dies back before bloom — plant around perennials that will conceal the yellowing leaves. Excellent drainage is essential; alliums rot in wet soils. Leave bulbs in place for naturalization; divide every 3–4 years when clusters become congested. Deadhead spent globes or leave for ornamental seedheads and self-sowing.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Alliums in Other Locations
Frequently Asked Questions
When should I plant Alliums in Marshall County, MN?
Marshall County is in Zone 3b with an average last frost of May 11. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, MN?
Marshall County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 11 and first fall frost is October 2.
When should I plant Alliums in Marshall County, MN?
In Marshall County, MN, plant Alliums after the last frost (around May 11) and before the first frost (around October 2). Best results when soil holds above 50°F.
What growing zone is Marshall County, MN for Alliums?
Marshall County sits in USDA Zone 3b. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.
Can Alliums grow in Marshall County's climate?
Yes — Alliums grows well in Marshall County's temperate climate. Marshall County averages a 144-day frost-free season, with last frost around May 11 and first frost around October 2.
Your Marshall County Garden Planner — Free
A 22-page printable planner built for Marshall County (Zone 3b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.