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When to Plant Geraniums in USDA Zone 5b

Zone 5b Zone 5b June

Your June gardening checklist

A quick June briefing for Zone 5b gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 1
Avg. first frost October 9
Get ahead of July
  • Starting indoors: geraniums
  • 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.

In Zone 5b, the average last spring frost is around April 18 and the first fall frost is around October 13, giving you a growing season of approximately 178 days.

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Zone 5b Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Geraniums Planting Timeline — Zone 5b

Where Is USDA Zone 5b?

The map below highlights the states that contain Zone 5b. Click any state to see the Geraniums planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Geraniums Planting Calendar — Zone 5b

Activity When Date Range
Start Indoors February 7 Feb 7 – Feb 21
Transplant Outdoors April 25 Apr 25 – May 9
Bloom July 4 Jul 4 – Sep 26

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
November
December

Free Zone 5b Planting Calendar PDF

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

70–100 days

Soil pH

6 – 7

Zone Temperature Range

-15°F to -10°F average annual minimum

Growing Season

178 days (Zone 5b average)

Planting Specifications

Planting Depth0.1 inches
Plant Spacing12 inches apart
Row Spacing14 inches between rows

Succession Planting Geraniums in Zone 5b

2
successive plantings in Zone 5b's ~178-day season

Sow every 8 weeks for continuous harvest throughout the season.

Growing Tips for Geraniums in Zone 5b

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.

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Saving Geraniums Seeds

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Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Frequently Asked Questions

When should I plant Geraniums in Zone 5b?

In Zone 5b, plan your Geraniums planting around the average last frost date of April 18. Start seeds indoors around February 7. Transplant seedlings around April 25.

Can Geraniums grow in Zone 5b?

Yes, Geraniums can grow well in Zone 5b, hardy in USDA zones 2a through 11b. Zone 5b has a growing season of approximately 178 days, which is sufficient for Geraniums (70-100 days to maturity).

When can I harvest Geraniums in Zone 5b?

In Zone 5b, expect to harvest Geraniums from July 4 – September 26. Geraniums takes 70-100 days from planting to harvest.

What is the last frost date for Zone 5b?

The average last spring frost in Zone 5b is around April 18, and the first fall frost is around October 13. This gives a growing season of approximately 178 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Geraniums?

Good companion plants for Geraniums include Lobelia, Sweet Alyssum, Petunias, Bachelors Button. These companions can help with pest control, pollination, and nutrient sharing.

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A 22-page printable planner tailored to Zone 5b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — 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.