Annual Geranium (Pelargonium) in Zone 4a & 4b

Pelargonium hortorum

When to plant annual geranium (pelargonium) in zone 4b

Zones 4a and 4b share the same average frost dates in our data, so this page covers both.

Method: Start indoors: Start indoors from seed, then transplant outside. Annual Geranium (Pelargonium) needs a head start most zones can't give it by direct-sowing alone.

Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1-1.5 ft.

Annual geranium is the classic bedding and container plant most gardeners know from nursery six-packs, but it's grown here from seed instead, which means starting well ahead of the season rather than buying an already-blooming plant.

How annual geranium (pelargonium) fits zone 4's season

Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Annual Geranium (Pelargonium) needs about 90 days from transplant to first harvest.

Good companions

No standout companions recorded yet for Annual Geranium (Pelargonium).

Where to buy annual geranium seeds

• Botanical Interests
• True Leaf Market
• Burpee
• High Mowing Organic Seeds

See why we recommend these suppliers →

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See it growing

Search YouTube for "growing annual geranium (pelargonium)" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)

← Back to the full zone 4b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →

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Growing Annual Geranium (Pelargonium) in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.

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