When to Plant Asparagus in Coos County, NH
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.
Coos County, New Hampshire is in USDA Zone 4a. The average last spring frost is May 18 and the first fall frost is September 30, giving you a growing season of approximately 135 days.
At an elevation of 604 feet, Coos County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Asparagus to ensure they mature before fall.
Coos County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.6
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.
Plant Water Budget
Asparagus Planting Timeline — Coos County, NH
Asparagus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 1 | Jun 1 – Jun 15 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
730–1095 days
Soil pH
6.5 – 7.5
USDA Zone
Zone 4a
Growing Season
135 days
Growing Tips for Coos County
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
Level Up Your Garden
Asparagus in Other Locations
Frequently Asked Questions
When should I plant Asparagus in Coos County, NH?
Coos County is in Zone 4a with an average last frost of May 18. Plan your Asparagus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Coos County, NH?
Coos County, New Hampshire is in USDA Hardiness Zone 4a. The average last spring frost is May 18 and first fall frost is September 30.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Coos County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.
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