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When to plant Tomatoes in Morrison, IL

Morrison's climate puts the Tomatoes spring window between April 23 and May 14. time plantings around the expected last-frost window for best survival.

When to Plant Tomatoes in Morrison, IL

Tomatoes
Whiteside County, Illinois Zone 5b June

Whiteside County, Illinois gardeners: here's your June plan

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

Avg. last frost April 16
Avg. first frost October 16
Soil temp (4") 69°F
Watering Moderate
Pest pressure High
Daylight 15 hrs
  1. Get tomatoes seeds going inside

    Label every cell. You will absolutely forget which is which otherwise.

Looking ahead to July
  • First harvests: tomatoes

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Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Morrison, Illinois is in USDA Zone 5b. The average last spring frost is April 16 and the first fall frost is October 16, giving you a growing season of approximately 183 days.

At an elevation of 682 feet, Whiteside County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Tomatoes to ensure they mature before fall.

Morrison, IL (Zone 5b) Moderate season
183 days
Last Spring Frost April 16
183 growing days
First Fall Frost October 16

Morrison Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Tomatoes Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Feb 13 Transplant: Apr 24 🍅 Harvest: Jun 26 – Sep 4
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Feb 19 Transplant: Apr 30 🍅 Harvest: Jul 2 – Sep 10
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Mar 7 Transplant: May 16 🍅 Harvest: Jul 18 – Sep 26

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 Morrison

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

3
successive plantings in your 183-day season

Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.

Tomatoes Water Budget

Plant needs
1.2″/week
Rainfall provides
0.7″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 826 gal / 100 sq ft

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 5.2" 3.3" 1.9" 💧 Light watering
May 5.2" 3.1" 2.1" 💧 Light watering
Jun 5.2" 3.7" 1.5" 💧 Light watering
Jul 5.2" 3.4" 1.8" 💧 Light watering
Aug 5.2" 3.3" 1.9" 💧 Light watering
Sep 5.2" 2.8" 2.4" 💧 Light watering
Oct 5.2" 2.3" 2.9" 🚿 Regular watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

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

Tomatoes 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.

Tomatoes needs ~942 GDD — county provides 2,379 GDD Excellent fit

Tomatoes Planting Timeline — Morrison, IL

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 23 Apr 23 – May 14
Harvest July 2 Jul 2 – Sep 10

Plant 0.5" deep · 24" apart · Rows 36" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

183 days in Whiteside County

Growing Tips for Tomatoes in Morrison

Direct sow Tomatoes outdoors after April 16 in Whiteside County when soil has warmed and frost danger has passed.

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

When should I plant Tomatoes in Morrison, IL?

In Morrison, IL, plant Tomatoes after the last frost (around April 16) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Morrison, IL for Tomatoes?

Morrison sits in USDA Zone 5b. Tomatoes grows reliably in zones 3a through 11b, so it's a good fit here.

Can Tomatoes grow in Morrison's climate?

Yes — Tomatoes grows well in Morrison's temperate climate. Morrison averages a 183-day frost-free season, with last frost around April 16 and first frost around October 16.

🌱

Your Whiteside County Garden Planner — Free

A 22-page printable planner built for Whiteside 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 Whiteside County, IL. Local conditions may vary. Last updated: June 2026.