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When to plant Geraniums in Adams County, IL

Adams County's short 189-day growing season means one Geraniums planting between April 21 and May 5. No fall crop in Zone 6a.

When to Plant Geraniums in Adams County, IL

Adams County, Illinois Zone 6a June

Top priorities for Adams County, Illinois gardeners in June

Your Adams County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 14
Avg. first frost October 20
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Time to start geraniums inside

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

  2. Collect geraniums at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Looking ahead to July
  • First harvests: geraniums

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Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.

Adams County, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 20, giving you a growing season of approximately 189 days.

At an elevation of 1,390 feet, Adams County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Geraniums during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Adams County, IL (Zone 6a) Moderate season
189 days
Last Spring Frost April 14
189 growing days
First Fall Frost October 20

Adams County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Jan 29 Transplant: Apr 16 🌸 Bloom: Jun 25 – Sep 24
Recommended (50%) ✓ Fits season (21 days to spare)
Start indoors: Feb 3 Transplant: Apr 21 🌸 Bloom: Jun 30 – Sep 29
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Feb 17 Transplant: May 5 🌸 Bloom: Jul 14 – Oct 13

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 Adams County

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

Soil pH

Your soil pH (6.2–7.3) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Geraniums will thrive.

How to Plant Geraniums

0.1"
Planting Depth
12"
Between Plants
14"
Between Rows

Succession Planting Geraniums

3
successive plantings in your 189-day season

Sow every 8 weeks. Last sowing by Jul 12 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 445 gal / 100 sq ft

Monthly Watering Guide for Geraniums

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

Month Geraniums Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Geraniums 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.

Geraniums needs ~1,169 GDD — county provides 2,598 GDD Excellent fit

Geraniums Planting Timeline — Adams County, IL

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 – Feb 17
Transplant Outdoors April 21 Apr 21 – May 5
Bloom June 30 Jun 30 – Sep 29

Plant 0.1" deep · 12" apart · Rows 14" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

189 days in Adams County

Growing Tips for Geraniums in Adams County

Direct sow Geraniums outdoors after April 14 in Adams County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Geraniums in Adams County, IL?

Adams County is in Zone 6a with an average last frost of April 14. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, IL?

Adams County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 20.

When should I plant Geraniums in Adams County, IL?

In Adams County, IL, plant Geraniums after the last frost (around April 14) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Adams County, IL for Geraniums?

Adams County sits in USDA Zone 6a. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Adams County's climate?

Yes — Geraniums grows well in Adams County's temperate climate. Adams County averages a 189-day frost-free season, with last frost around April 14 and first frost around October 20.

🌱

Your Adams County Garden Planner — Free

A 22-page printable planner built for Adams County (Zone 6a). 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 Adams County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.