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When to Plant Scarlet Runner Beans in Hillsborough County, NH

Hillsborough County, New Hampshire Zone 6a May

This month in Hillsborough County, New Hampshire

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Hillsborough County, New Hampshire.

Avg. last frost May 2
Avg. first frost October 11
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Move scarlet runner beans from tray to bed

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Seed scarlet runner beans outdoors

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

To set up a strong June, finish these tasks
  • Starting indoors: scarlet runner beans

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Scarlet runner beans are ornamental and edible climbing beans with vivid red flowers that attract hummingbirds. Both the young pods and mature beans are edible.

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 Scarlet Runner Beans 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 (49 days to spare)
Start indoors: Mar 2 Transplant: May 11 🍅 Harvest: Jul 13 – Aug 17
Recommended (50%) ✓ Fits season (50 days to spare)
Start indoors: Mar 7 Transplant: May 16 🍅 Harvest: Jul 18 – Aug 22
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Mar 22 Transplant: May 31 🍅 Harvest: Aug 2 – Sep 6

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 Scarlet Runner Beans's growing requirements.

Soil pH

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

Soil Texture

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

Drainage

Drainage is adequate for Scarlet Runner Beans.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Scarlet Runner Beans.

How to Plant Scarlet Runner Beans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Scarlet Runner Beans

3
successive plantings in your 162-day season

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

Plant Water Budget

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

Monthly Watering Guide for Scarlet Runner Beans

Scarlet Runner Beans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Scarlet Runner Beans 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 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
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.

Scarlet Runner Beans 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.

Scarlet Runner Beans needs ~910 GDD — county provides 2,106 GDD Excellent fit

Scarlet Runner Beans Planting Timeline — Hillsborough County, NH

Scarlet Runner Beans Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest July 18 Jul 18 – Aug 22

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/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 Scarlet Runner Beans in Hillsborough County

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

Common pests for Scarlet Runner Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Provide tall trellising for vigorous vines. Direct sow after frost. Harvest pods young for snap beans or let mature for shelling beans. Tubers are perennial in mild climates.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Scarlet Runner Beans in Hillsborough County, NH?

Hillsborough County is in Zone 6a with an average last frost of May 2. Plan your Scarlet Runner Beans 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

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