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When to Plant Persimmon in Iroquois County, IL

Iroquois County, Illinois Zone 5b May

What to do in May

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

Avg. last frost April 18
Avg. first frost October 13
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Move persimmon from tray to bed

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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Persimmons are ornamental trees producing sweet, honey-flavored fruits in fall. American persimmons are astringent until fully ripe while Asian types can be eaten firm.

Iroquois County, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 13, giving you a growing season of approximately 178 days.

At an elevation of 1,345 feet, Iroquois County receives approximately 30 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Persimmon during the growing season.

Iroquois County, IL (Zone 5b) Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Iroquois 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
Transplant: May 4
Recommended (50%) ✓ Fits season
Transplant: May 9
Safe Start (90%) ✓ Fits season
Transplant: May 27

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 Iroquois County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Persimmon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Persimmon.

Organic Matter

Organic matter is excellent (4.5%) — Persimmon will thrive.

How to Plant Persimmon

120"
Between Plants
144"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,126 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Persimmon

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

Month Persimmon Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 3.6" 0.7" 💧 Light watering
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Persimmon 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.

Persimmon needs ~25,094 GDD — county provides 2,447 GDD May not mature

Persimmon Planting Timeline — Iroquois County, IL

Persimmon Planting Calendar

Activity When Date Range
Transplant Outdoors May 9 May 9 – May 23

· 120" apart · Rows 144" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

1095–2555 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

178 days in Iroquois County

Growing Tips for Persimmon in Iroquois County

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

Your 178.0-day growing season in Iroquois County is tight for Persimmon (1095.0-2555.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Choose self-fertile varieties or plant male and female trees. American types must be fully soft-ripe before eating. Asian varieties may be eaten when firm. Minimal pruning needed.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Persimmon in Iroquois County, IL?

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

What planting zone is Iroquois County, IL?

Iroquois County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 18 and first fall frost is October 13.

🌱

Your Iroquois County Garden Planner — Free

A 24-page printable planner built for Iroquois 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 Iroquois 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.