When to Plant Scarlet Runner Beans in Grafton County, NH
May in Grafton County, New Hampshire — your action list
Here's what deserves your attention in Grafton County, New Hampshire this month. Everything below is tailored to Zone 5a and timed around your local frost dates.
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Set out scarlet runner beans seedlings
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Outdoor sowing time: scarlet runner beans
Mark the row. Birds and stray feet both have opinions about unmarked beds.
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.
Grafton County, New Hampshire is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 7, giving you a growing season of approximately 148 days.
At an elevation of 524 feet, Grafton County receives approximately 44.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Scarlet Runner Beans to ensure they mature before fall.
Grafton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.3
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 Grafton County
How your county's soil matches Scarlet Runner Beans's growing requirements.
Soil pH
Your soil pH (5.2–6.3) 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 Grafton County is excellent for Scarlet Runner Beans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.5%). Annual compost additions will help Scarlet Runner Beans.
How to Plant Scarlet Runner Beans
Succession Planting Scarlet Runner Beans
Sow every 6.9 weeks. Last sowing by Jul 19 to harvest before frost.
Plant Water Budget
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 | — | 3.5" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 3.2" | 0" | ❄️ Dormant |
| Apr | — | 3.9" | 0" | ❄️ Dormant |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Nov | — | 3.5" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Grafton 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 Planting Timeline — Grafton County, NH
Scarlet Runner Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | May 26 | May 26 – Jun 9 |
| Direct Sow | May 19 | May 19 – Jun 9 |
| Harvest | July 28 | Jul 28 – Sep 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| 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 5a
📆 Growing Season
148 days in Grafton County
Growing Tips for Scarlet Runner Beans in Grafton County
Direct sow Scarlet Runner Beans outdoors after May 12 in Grafton 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
Check more plant combinations with our Companion Planting Checker →
Scarlet Runner Beans in Other Locations
Frequently Asked Questions
When should I plant Scarlet Runner Beans in Grafton County, NH?
Grafton County is in Zone 5a with an average last frost of May 12. Plan your Scarlet Runner Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grafton County, NH?
Grafton County, New Hampshire is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 7.
Your Grafton County Garden Planner — Free
A 24-page printable planner built for Grafton 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.