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When to Plant Cress in McHenry County, IL

McHenry County, Illinois Zone 5b May

May in the garden — McHenry County, Illinois

We've pulled the most time-sensitive tasks for McHenry County, Illinois this May and put them front and centre. Tackle them in order.

Avg. last frost April 18
Avg. first frost October 20
Soil temp (4") 57°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Indoor seed-starting week for cress

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. It's harvest week for cress

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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Garden cress is one of the fastest-growing edibles, producing peppery sprouts in as little as two weeks. It is excellent for microgreens and garnishes.

McHenry County, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 20, giving you a growing season of approximately 185 days.

At an elevation of 640 feet, McHenry County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Cress to ensure they mature before fall.

McHenry County, IL (Zone 5b) Moderate season
185 days
Last Spring Frost April 18
185 growing days
First Fall Frost October 20
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McHenry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (146 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Apr 27 – May 18
Recommended (50%) ✓ Fits season (150 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: May 2 – May 23
Safe Start (90%) ✓ Fits season (149 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: May 18 – Jun 8

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 McHenry County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Cress's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Cress will thrive.

How to Plant Cress

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Cress

16
successive plantings in your 185-day season

Sow every 1.6 weeks. Last sowing by Sep 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 208 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Cress

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

Month Cress Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Cress 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.

Cress needs ~228 GDD — county provides 2,405 GDD Excellent fit

Cress Planting Timeline — McHenry County, IL

Cress Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest May 2 May 2 – May 23
Fall Sowing August 11 Aug 11 – Aug 25

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

14–21 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

185 days in McHenry County

Growing Tips for Cress in McHenry County

Direct sow Cress outdoors after April 18 in McHenry County when soil has warmed and frost danger has passed.

Your generous 185.0-day season in McHenry County allows multiple plantings of Cress. Sow every 7.0 days for continuous harvest.

Common pests for Cress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds thickly on moist soil or paper towels. Keep moist and harvest when 2-3 inches tall. Succession sow every few days for continuous supply. Grows well indoors year-round.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cress in McHenry County, IL?

McHenry County is in Zone 5b with an average last frost of April 18. Plan your Cress planting based on this frost date — see the calendar above for exact timing.

What planting zone is McHenry County, IL?

McHenry County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 18 and first fall frost is October 20.

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Your McHenry County Garden Planner — Free

A 24-page printable planner built for McHenry County (Zone 5b). 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 McHenry County, IL. 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.