When to Plant Asparagus in Olmsted County, MN
May to-do list for Olmsted County, Minnesota
Your garden in Olmsted County, Minnesota is working on a schedule, even when you're not. Here's where you should be this May.
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Harden off and plant asparagus
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
Asparagus is a long-lived perennial vegetable that produces tender spears each spring for 15-20 years once established. It requires patience but rewards with reliable harvests.
Olmsted County, Minnesota is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 4, giving you a growing season of approximately 154 days.
At an elevation of 992 feet, Olmsted County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Asparagus to ensure they mature before fall.
Olmsted County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.3
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 Olmsted County
How your county's soil matches Asparagus's growing requirements.
Soil pH
Your soil pH (5.9–7.3) overlaps with Asparagus's range (6.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Olmsted County is excellent for Asparagus — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Asparagus.
Organic Matter
Organic matter is moderate (3.8%). Annual compost additions will help Asparagus.
How to Plant Asparagus
Plant Water Budget
Monthly Watering Guide for Asparagus
Asparagus needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Asparagus Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Sep | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Oct | 3.5" | 2.4" | 1.1" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Olmsted County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Asparagus 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.
Asparagus Planting Timeline — Olmsted County, MN
Asparagus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 17 | May 17 – May 31 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
154 days in Olmsted County
Growing Tips for Asparagus in Olmsted County
Direct sow Asparagus outdoors after May 03 in Olmsted County when soil has warmed and frost danger has passed.
Your 154.0-day growing season in Olmsted County is tight for Asparagus (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant crowns in deep trenches with compost. Do not harvest spears for the first two years to allow root establishment. Mulch heavily to suppress weeds and retain moisture.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Asparagus in Other Locations
Frequently Asked Questions
When should I plant Asparagus in Olmsted County, MN?
Olmsted County is in Zone 4b with an average last frost of May 3. Plan your Asparagus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Olmsted County, MN?
Olmsted County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 3 and first fall frost is October 4.
Your Olmsted County Garden Planner — Free
A 24-page printable planner built for Olmsted County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.