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When to Plant Parsley in Hillsborough County, NH

Hillsborough County, New Hampshire Zone 6a May

Hillsborough County, New Hampshire gardeners: here's your May plan

Your garden in Hillsborough County, New Hampshire is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 2
Avg. first frost October 11
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
June will be here before you know it — start on
  • Starting indoors: parsley
  • First harvests: parsley

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Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.

Hillsborough County, New Hampshire is in USDA Zone 6a. The average last spring frost is May 2 and the first fall frost is October 11, giving you a growing season of approximately 162 days.

At an elevation of 145 feet, Hillsborough County receives approximately 44 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Parsley to ensure they mature before fall.

Hillsborough County, NH (Zone 6a) Moderate season
162 days
Last Spring Frost May 2
162 growing days
First Fall Frost October 11

Hillsborough County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Mar 23 Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 24
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Mar 28 Transplant: Apr 25 🍅 Harvest: Jun 27 – Aug 29
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: Apr 12 Transplant: May 10 🍅 Harvest: Jul 12 – Sep 13

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 Hillsborough County

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

Soil pH

Your soil pH (4.9–6.6) is more acidic than Parsley prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Parsley.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Parsley.

How to Plant Parsley

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Parsley

3
successive plantings in your 162-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
0.6″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Parsley

Parsley needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Parsley Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 4.4" 0" ❄️ Dormant
May 2.6" 4.2" 0" ✅ Rainfall sufficient
Jun 2.6" 3.7" 0" ✅ Rainfall sufficient
Jul 2.6" 4.6" 0" ✅ Rainfall sufficient
Aug 2.6" 3.5" 0" ✅ Rainfall sufficient
Sep 2.6" 4.2" 0" ✅ Rainfall sufficient
Oct 2.6" 3.8" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

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

Parsley 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.

Parsley needs ~910 GDD — county provides 2,106 GDD Excellent fit

Parsley Planting Timeline — Hillsborough County, NH

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 18 Apr 18 – May 9
Harvest June 27 Jun 27 – Aug 29
Fall Sowing August 2 Aug 2 – Aug 16

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6a

📆 Growing Season

162 days in Hillsborough County

Growing Tips for Parsley in Hillsborough County

Direct sow Parsley outdoors after May 02 in Hillsborough County when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.

Companion Planting

Good Companions

Avoid Planting Near

  • Mint
  • Lettuce

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Parsley in Hillsborough County, NH?

Hillsborough County is in Zone 6a with an average last frost of May 2. Plan your Parsley planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hillsborough County, NH?

Hillsborough County, New Hampshire is in USDA Hardiness Zone 6a. The average last spring frost is May 2 and first fall frost is October 11.

🌱

Your Hillsborough County Garden Planner — Free

A 24-page printable planner built for Hillsborough County (Zone 6a). 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 Hillsborough County, NH. Local conditions may vary. Last updated: May 2026.

Sources & credits

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