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When to Plant Cilantro in Rusk County, WI

Rusk County, Wisconsin Zone 4a May

Top priorities for Rusk County, Wisconsin gardeners in May

A quick May briefing for Rusk County, Wisconsin gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 16
Avg. first frost September 28
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Plant out cilantro

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Direct-sow cilantro

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Get ahead of 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.

Rusk County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 16 and the first fall frost is September 28, giving you a growing season of approximately 135 days.

At an elevation of 1,112 feet, Rusk County receives approximately 38.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Cilantro to ensure they mature before fall.

Rusk County, WI (Zone 4a) Short season
135 days
Last Spring Frost May 16
135 growing days
First Fall Frost September 28

Rusk County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jun 15 – Aug 17
Recommended (50%) ✓ Fits season (37 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: Jun 20 – Aug 22
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: Apr 17 Transplant: May 22 🍅 Harvest: Jul 3 – Sep 4

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 Rusk County

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

Soil pH

Your soil pH (6.1–7.0) is within Cilantro's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — 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

3
successive plantings in your 135-day season

Sow every 4.6 weeks. Last sowing by Jul 30 to harvest before frost.

For a dedicated fall crop, sow by Jul 06.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.2″/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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4.4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.7" 0" ✅ Rainfall sufficient
Oct 2.8" 0" ❄️ Dormant
Nov 2.9" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Rusk 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 ~500 GDD — county provides 1,350 GDD Excellent fit

Cilantro Planting Timeline — Rusk County, WI

Cilantro Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors May 9 May 9 – May 23
Direct Sow May 9 May 9 – May 30
Harvest June 20 Jun 20 – Aug 22
Fall Sowing July 6 Jul 6 – Jul 20

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

Month-by-Month Timeline

MonthActivities
January
February
March
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: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

135 days in Rusk County

Growing Tips for Cilantro in Rusk County

Direct sow Cilantro outdoors after May 16 in Rusk 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 Rusk County, WI?

Rusk County is in Zone 4a with an average last frost of May 16. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rusk County, WI?

Rusk County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 16 and first fall frost is September 28.

🌱

Your Rusk County Garden Planner — Free

A 24-page printable planner built for Rusk 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 Rusk County, WI. 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.