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When to Plant Carrots in Belknap County, NH

Belknap County, New Hampshire Zone 5a April

Your April gardening checklist

We've pulled the most time-sensitive tasks for Belknap County, New Hampshire this April and put them front and centre. Tackle them in order.

Avg. last frost May 3
Avg. first frost October 11
Soil temp (4") 44°F
Watering Low
Pest pressure Low
Daylight 13.2 hrs
  1. Plant carrots from seed, right in the garden

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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Carrots are a popular root vegetable available in orange, purple, white, and yellow varieties. They are rich in beta-carotene and have a sweet, earthy flavor.

Belknap County, New Hampshire is in USDA Zone 5a. The average last spring frost is May 3 and the first fall frost is October 11, giving you a growing season of approximately 161 days.

At an elevation of 764 feet, Belknap County receives approximately 48.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Carrots during the growing season.

Belknap County, NH (Zone 5a) Moderate season
161 days
Last Spring Frost May 3
161 growing days
First Fall Frost October 11

Belknap County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (63 days to spare)
Transplant: Apr 28 🍅 Harvest: Jun 30 – Aug 4
Recommended (50%) ✓ Fits season (63 days to spare)
Transplant: May 3 🍅 Harvest: Jul 5 – Aug 9
Safe Start (90%) ✓ Fits season (67 days to spare)
Transplant: May 17 🍅 Harvest: Jul 19 – Aug 23

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 Belknap County

How your county's soil matches Carrots's growing requirements.

Soil pH

Your soil pH (4.8–6.8) is more acidic than Carrots prefers (6.0–6.8). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Belknap County is excellent for Carrots — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Carrots.

How to Plant Carrots

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Carrots

3
successive plantings in your 161-day season

Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 02.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Carrots

Carrots 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 Carrots Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 3.9" 0" ❄️ Dormant
May 3.5" 3.9" 0" ✅ Rainfall sufficient
Jun 3.5" 4.7" 0" ✅ Rainfall sufficient
Jul 3.5" 4.9" 0" ✅ Rainfall sufficient
Aug 3.5" 4.8" 0" ✅ Rainfall sufficient
Sep 3.5" 3.8" 0" ✅ Rainfall sufficient
Oct 3.5" 4.4" 0" ✅ Rainfall sufficient
Nov 3.8" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Belknap County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Carrots 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.

Carrots needs ~1,068 GDD — county provides 2,455 GDD Excellent fit

Carrots Planting Timeline — Belknap County, NH

Carrots Planting Calendar

Activity When Date Range
Direct Sow April 19 Apr 19 – May 10
Harvest June 21 Jun 21 – Jul 26
Fall Sowing August 2 Aug 2 – Aug 16

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June Harvest
July Harvest
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–6.8 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

161 days in Belknap County

Growing Tips for Carrots in Belknap County

Direct sow Carrots outdoors after May 03 in Belknap County when soil has warmed and frost danger has passed.

Common pests for Carrots in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds directly in loose, stone-free soil for straight roots. Keep soil moist until germination which can take 2-3 weeks. Thin seedlings to 2 inches apart.

Companion Planting

Good Companions

Avoid Planting Near

  • Dill
  • Parsnip

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Carrots Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Replant roots for 2nd year flowers. Harvest umbels when brown.
Storage Store airtight; viable 3 years at 35°F, under 50% humidity.

Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial — requires two seasons.

Frequently Asked Questions

When should I plant Carrots in Belknap County, NH?

Belknap County is in Zone 5a with an average last frost of May 3. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.

What planting zone is Belknap County, NH?

Belknap County, New Hampshire is in USDA Hardiness Zone 5a. The average last spring frost is May 3 and first fall frost is October 11.

🌱

Your Belknap County Garden Planner — Free

A 24-page printable planner built for Belknap County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Belknap County, NH. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.