When to Plant Parsnip in Lewis County, ID
This month in Lewis County, Idaho
A quick May briefing for Lewis County, Idaho gardeners — what's urgent, what's next, and what can wait.
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Put parsnip seeds straight in the ground
Mark the row. Birds and stray feet both have opinions about unmarked beds.
Parsnips are a sweet, nutty root vegetable that develops best flavor after exposure to frost. They require a long growing season but reward patient gardeners.
Lewis County, Idaho is in USDA Zone 6b. The average last spring frost is May 20 and the first fall frost is September 23, giving you a growing season of approximately 126 days.
At an elevation of 4,861 feet, Lewis County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Parsnip during the growing season. With low rainfall, drip irrigation is essential for growing Parsnip successfully. Mulch heavily to conserve soil moisture.
Lewis County Soil Profile
Soil Type
Loam
Soil pH
6.7-8
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 Lewis County
How your county's soil matches Parsnip's growing requirements.
Soil pH
Your soil pH (6.7–8.0) is more alkaline than Parsnip prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Lewis County is excellent for Parsnip — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Parsnip.
How to Plant Parsnip
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Parsnip
Parsnip needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Parsnip Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Jun | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Jul | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Aug | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Sep | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Oct | — | 1.3" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lewis County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Parsnip 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.
Parsnip Planting Timeline — Lewis County, ID
Parsnip Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 6 | May 6 – May 27 |
| Harvest | August 19 | Aug 19 – Sep 30 |
| Fall Sowing | July 15 | Jul 15 – Jul 29 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | — |
| July | Fall Sowing |
| 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
100–130 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6b
📆 Growing Season
126 days in Lewis County
Growing Tips for Parsnip in Lewis County
Direct sow Parsnip outdoors after May 20 in Lewis County when soil has warmed and frost danger has passed.
Your 126.0-day growing season in Lewis County is tight for Parsnip (100.0-130.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Parsnip in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
Lewis County receives only 14" of rain annually. Parsnip needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Use only fresh seed as parsnip seed viability declines rapidly. Sow directly in spring in deeply worked soil. Leave roots in the ground through winter for sweetest flavor.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Parsnip in Other Locations
Frequently Asked Questions
When should I plant Parsnip in Lewis County, ID?
Lewis County is in Zone 6b with an average last frost of May 20. Plan your Parsnip planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lewis County, ID?
Lewis County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 20 and first fall frost is September 23.
Your Lewis County Garden Planner — Free
A 24-page printable planner built for Lewis County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.