Annual Geranium (Pelargonium) in Zone 3a & 3b
Pelargonium hortorum
Yes, annual geranium (pelargonium) grows in zones 3a and 3b. Start seeds indoors Mar 28–Apr 4 and plant out Jun 6–Jun 13.
When to plant annual geranium (pelargonium) in zone 3b
Zones 3a and 3b share the same average frost dates, so this page covers both.
Method: Start indoors: Start indoors from seed, then transplant outside. It needs a head start most zones can't give it by direct-sowing alone.
| Start indoors | Mar 28–Apr 4 |
|---|---|
| Direct sow / transplant outside | Jun 6–Jun 13 |
| Estimated bloom | Sep 4–Sep 11 (~90 days after transplanting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1-1.5 ft.
Plant alongside it in zone 3b
These go outside within two weeks of annual geranium (pelargonium) in zone 3b, so one planting day can cover them.
- NasturtiumJun 6–Jun 13
- MarigoldJun 6–Jun 13
- Ageratum (Flossflower)Jun 6–Jun 13
- Butterfly Weed (Asclepias)Jun 6–Jun 13
- Campanula (Bellflower)Jun 6–Jun 13
- Castor BeanJun 6–Jun 13
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 3's season
Zone 3b's frost-free window runs about 98 days, from May 30 to September 5. Annual geranium (pelargonium) needs about 90 days from transplant to first bloom.
Annual Geranium (Pelargonium) planting windows in every zone
Zone 3b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Bloom |
|---|---|---|---|
| 2a & 2b | Mar 18–Mar 25 | May 27–Jun 3 | Aug 25–Sep 1 |
| 3a & 3b (your zone) | Mar 28–Apr 4 | Jun 6–Jun 13 | Sep 4–Sep 11 |
| 4a & 4b | Mar 13–Mar 20 | May 22–May 29 | Aug 20–Aug 27 |
| 5a & 5b | Mar 8–Mar 15 | May 17–May 24 | Aug 15–Aug 22 |
| 6a & 6b | Feb 21–Feb 28 | May 2–May 9 | Jul 31–Aug 7 |
| 7a & 7b | Feb 6–Feb 13 | Apr 17–Apr 24 | Jul 16–Jul 23 |
| 8a & 8b | Jan 21–Jan 28 | Apr 1–Apr 8 | Jun 30–Jul 7 |
| 9a & 9b | Dec 14–Dec 21 | Feb 22–Mar 1 | May 23–May 30 |
| 10a & 10b | Nov 28–Dec 5 | Feb 6–Feb 13 | May 7–May 14 |
| 11a & 11b | Oct 30–Nov 6 | Jan 8–Jan 15 | Apr 8–Apr 15 |
Bloom dates are about 90 days after the sow or plant-out date, not after starting seeds indoors.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
Good companions
No well-established companions for annual geranium (pelargonium).
Where to buy annual geranium seeds
None of the seed suppliers we list carries annual geranium seeds right now. A local garden center or a specialty seed house is the place to look.
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 3b calendar · Plan your beds in the Garden Designer →
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Growing Annual Geranium (Pelargonium) in USDA zone 3b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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