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When to Plant Cilantro in Brown County, SD

Brown County, South Dakota Zone 4a May

Your May game plan for Brown County, South Dakota

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

Avg. last frost May 8
Avg. first frost October 4
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Time to transplant cilantro

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Plant cilantro from seed, right in the garden

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

A few tasks this May that'll pay off in June
  • Starting indoors: cilantro
  • First harvests: cilantro

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Cilantro is a dual-purpose herb providing fresh leaves (cilantro) and dried seeds (coriander). It bolts quickly in heat, producing flowers beloved by beneficial insects.

Brown County, South Dakota is in USDA Zone 4a. The average last spring frost is May 8 and the first fall frost is October 4, giving you a growing season of approximately 149 days.

At an elevation of 536 feet, Brown County receives approximately 34.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Cilantro to ensure they mature before fall.

Brown County, SD (Zone 4a) Short season
149 days
Last Spring Frost May 8
149 growing days
First Fall Frost October 4

Brown County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 4 – Aug 6
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 12 – Aug 14
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: Jun 22 – Aug 24

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 Brown County

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

Soil pH

Your soil pH (6.3–7.6) overlaps with Cilantro's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Brown County is excellent for Cilantro — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.0%) — Cilantro will thrive.

How to Plant Cilantro

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Cilantro

4
successive plantings in your 149-day season

Sow every 4.6 weeks. Last sowing by Aug 05 to harvest before frost.

For a dedicated fall crop, sow by Jul 12.

Plant Water Budget

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

Monthly Watering Guide for Cilantro

Cilantro 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 Cilantro Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.6" 0" ❄️ Dormant
May 2.2" 5.1" 0" ✅ Rainfall sufficient
Jun 2.2" 5.7" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Cilantro 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.

Cilantro needs ~650 GDD — county provides 1,937 GDD Excellent fit

Cilantro Planting Timeline — Brown County, SD

Cilantro Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 1 May 1 – May 15
Direct Sow May 1 May 1 – May 22
Harvest June 12 Jun 12 – Aug 14
Fall Sowing July 12 Jul 12 – Jul 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

149 days in Brown County

Growing Tips for Cilantro in Brown County

Direct sow Cilantro outdoors after May 08 in Brown County when soil has warmed and frost danger has passed.

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

General growing tips

Succession sow every 2-3 weeks. Provide afternoon shade in warm weather. Harvest leaves before flowering or allow some plants to go to seed for coriander and self-sowing.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cilantro in Brown County, SD?

Brown County is in Zone 4a with an average last frost of May 8. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Brown County, SD?

Brown County, South Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 8 and first fall frost is October 4.

🌱

Your Brown County Garden Planner — Free

A 24-page printable planner built for Brown County (Zone 4a). 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 Brown County, SD. 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.