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When to plant Geraniums in Saint Patrick, MO

In Saint Patrick, Geraniums is a single-season spring crop — there's no second fall window. Plant April 23–May 7 for an 70–100-day harvest, finishing well before the October 18 first frost.

When to Plant Geraniums in Saint Patrick, MO

Clark County, Missouri Zone 6a June

Top priorities for Clark County, Missouri gardeners in June

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 16
Avg. first frost October 18
Soil temp (4") 69°F
Watering Moderate
Pest pressure High
Daylight 14.9 hrs
  1. Begin indoor sowing: geraniums

    These need a head start before your last frost (April 16). Sow into cells now so you're ready to transplant in a few weeks.

To set up a strong July, finish these tasks
  • 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.

Saint Patrick, Missouri is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 18, giving you a growing season of approximately 185 days.

At an elevation of 833 feet, Clark County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Geraniums during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Saint Patrick, MO (Zone 6a) Moderate season
185 days
Last Spring Frost April 16
185 growing days
First Fall Frost October 18

Saint Patrick Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Jan 30 Transplant: Apr 17 🌸 Bloom: Jun 26 – Sep 25
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Feb 5 Transplant: Apr 23 🌸 Bloom: Jul 2 – Oct 1
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Feb 21 Transplant: May 9 🌸 Bloom: Jul 18 – Oct 17

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 Saint Patrick

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

Soil pH

Your soil pH (5.6–6.6) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Geraniums.

How to Plant Geraniums

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

Succession Planting Geraniums

3
successive plantings in your 185-day season

Sow every 8 weeks. Last sowing by Jul 10 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 413 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 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clark 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 ~1,296 GDD — county provides 2,821 GDD Excellent fit

Geraniums Planting Timeline — Saint Patrick, MO

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 – Feb 19
Transplant Outdoors April 23 Apr 23 – May 7
Bloom July 2 Jul 2 – Oct 1

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
July Bloom
August Bloom
September Bloom
October Bloom
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

185 days in Clark County

Growing Tips for Geraniums in Saint Patrick

Direct sow Geraniums outdoors after April 16 in Clark 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 →

When should I plant Geraniums in Saint Patrick, MO?

In Saint Patrick, MO, plant Geraniums after the last frost (around April 16) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Saint Patrick, MO for Geraniums?

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

Can Geraniums grow in Saint Patrick's climate?

Yes — Geraniums grows well in Saint Patrick's temperate climate. Saint Patrick averages a 185-day frost-free season, with last frost around April 16 and first frost around October 18.

🌱

Your Clark County Garden Planner — Free

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