Blog

When to Plant Marigolds in Robeson County, NC

Robeson County, North Carolina Zone 8b May

Robeson County, North Carolina gardeners: here's your May plan

Your Robeson County, North Carolina garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 24
Avg. first frost November 6
Soil temp (4") 71°F
Watering Moderate
Pest pressure High
Daylight 13.8 hrs
  1. Basket week: marigolds

    If you can't use it all right away, check the food-preservation section of your planner.

Looking ahead to June
  • First harvests: marigolds

Instant PDF download. No spam, unsubscribe any time.

Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

Robeson County, North Carolina is in USDA Zone 8b. The average last spring frost is March 24 and the first fall frost is November 6, giving you a growing season of approximately 227 days.

At an elevation of 887 feet, Robeson County receives approximately 49.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97°F, so Marigolds may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Marigolds, but amend with compost to improve drainage and prevent root rot.

Robeson County, NC (Zone 8b) Long season
227 days
Last Spring Frost March 24
227 growing days
First Fall Frost November 6

Robeson County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Apr 20 Transplant: Mar 2 🍅 Harvest: Apr 27 – Sep 14
Recommended (50%) ✓ Fits season (45 days to spare)
Start indoors: Apr 28 Transplant: Mar 10 🍅 Harvest: May 5 – Sep 22
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: May 21 Transplant: Apr 2 🍅 Harvest: May 28 – Oct 15

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 Robeson County

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

Soil pH

Your soil pH (5.3–6.2) is more acidic than Marigolds prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Robeson County is excellent for Marigolds — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Marigolds.

How to Plant Marigolds

0.3"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Marigolds

5
successive plantings in your 227-day season

Sow every 5.7 weeks. Last sowing by Aug 28 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Marigolds

Marigolds needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Marigolds Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 2.2" 4.9" 0" ✅ Rainfall sufficient
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 5" 0" ✅ Rainfall sufficient
Aug 2.2" 5.3" 0" ✅ Rainfall sufficient
Sep 2.2" 3.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.2" 3.3" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

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

Marigolds 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.

Marigolds needs ~1,365 GDD — county provides 5,164 GDD Excellent fit

Marigolds Planting Timeline — Robeson County, NC

Marigolds Planting Calendar

Activity When Date Range
Start Indoors April 28 Apr 28 – May 12
Transplant Outdoors March 10 Mar 10 – Mar 24
Direct Sow March 10 Mar 10 – Mar 31
Harvest May 5 May 5 – Sep 22

Plant 0.3" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

227 days in Robeson County

Growing Tips for Marigolds in Robeson County

Direct sow Marigolds outdoors after March 24 in Robeson County when soil has warmed and frost danger has passed.

With Robeson County's clay soil (31% clay), work in 3-4 inches of compost before planting Marigolds. Avoid tilling when soil is wet to prevent compaction.

With summer highs reaching 97°F in Robeson County, provide afternoon shade for Marigolds and water deeply in the morning.

Common pests for Marigolds in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Cabbage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Marigolds Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower heads dry on plant. Pull dried petals to reveal seeds.
Storage Store in envelopes; viable 3 years at 35°F, under 50% humidity.

Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.

Frequently Asked Questions

When should I plant Marigolds in Robeson County, NC?

Robeson County is in Zone 8b with an average last frost of March 24. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Robeson County, NC?

Robeson County, North Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 24 and first fall frost is November 6.

🌱

Your Robeson County Garden Planner — Free

A 24-page printable planner built for Robeson County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Robeson County, NC. 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.