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When to Plant Geraniums in Marshall County, OK

Marshall County, Oklahoma Zone 8a June

Your June game plan for Marshall County, Oklahoma

Here's what deserves your attention in Marshall County, Oklahoma this month. Everything below is tailored to Zone 8a and timed around your local frost dates.

Avg. last frost March 24
Avg. first frost November 12
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 14.3 hrs
  1. Get geraniums seeds going inside

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Harvest geraniums as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Coming up in July — start thinking about
  • 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.

Marshall County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 24 and the first fall frost is November 12, giving you a growing season of approximately 233 days.

At an elevation of 520 feet, Marshall County receives approximately 23.7 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Geraniums during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Marshall County, OK (Zone 8a) Long season
233 days
Last Spring Frost March 24
233 growing days
First Fall Frost November 12
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Marshall County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Dec 31 Transplant: Mar 4 🌸 Bloom: May 13 – Sep 30
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Jan 13 Transplant: Mar 17 🌸 Bloom: May 26 – Oct 13
Safe Start (90%) ✓ Fits season (27 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🌸 Bloom: Jun 16 – Nov 3

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 Marshall County

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

Soil pH

Your soil pH (6.2–7.8) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Geraniums.

Organic Matter

Organic matter is moderate (3.5%). 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 233-day season

Sow every 8 weeks. Last sowing by Aug 04 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,172 gal / 100 sq ft
Drought risk

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

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 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 4.3" 1.6" 2.7" 🚿 Regular watering
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 1.3" 3" 🚿 Regular watering
Nov 4.3" 0.9" 3.4" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Marshall 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 ~1,615 GDD — county provides 4,427 GDD Excellent fit

Geraniums Planting Timeline — Marshall County, OK

Geraniums Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors March 17 Mar 17 – Mar 31
Bloom May 26 May 26 – Oct 13

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

233 days in Marshall County

Growing Tips for Geraniums in Marshall County

Direct sow Geraniums outdoors after March 24 in Marshall County when soil has warmed and frost danger has passed.

Marshall County receives only 24" of rain annually. Geraniums needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Marshall County, OK?

Marshall County is in Zone 8a with an average last frost of March 24. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marshall County, OK?

Marshall County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 24 and first fall frost is November 12.

🌱

Your Marshall County Garden Planner — Free

A 22-page printable planner built for Marshall County (Zone 8a). 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 Marshall County, OK. 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.