| Plant | Zone 3b | Zone 3b |
|---|---|---|
| Zinnia | Plant outside: May 23 to Jun 27 Start seeds indoors: around Apr 25 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Apr 25 |
| French marigold | Plant outside: May 23 to Jun 27 Start seeds indoors: around Apr 11 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Apr 11 |
| Petunia | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 |
| Cosmos | Plant outside: May 23 to Jun 27 | Plant outside: May 23 to Jun 27 |
| Sunflower | Plant outside: May 23 to Jun 27 | Plant outside: May 23 to Jun 27 |
| Impatiens | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 |
| Wax begonia | Plant outside: May 23 to Jun 27 Start seeds indoors: around Feb 28 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Feb 28 |
| Zonal geranium | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 |
| Snapdragon | Plant outside: Apr 18 to May 16 Start seeds indoors: around Feb 21 Fall planting: Aug 7 to Sep 4 | Plant outside: Apr 18 to May 16 Start seeds indoors: around Feb 21 Fall planting: Aug 7 to Sep 4 |
| Pansy | Plant outside: Apr 18 to May 16 Start seeds indoors: around Feb 7 Fall planting: Aug 7 to Sep 4 | Plant outside: Apr 18 to May 16 Start seeds indoors: around Feb 7 Fall planting: Aug 7 to Sep 4 |
| Sweet alyssum | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 |
| Celosia | Plant outside: May 23 to Jun 27 Start seeds indoors: around Apr 11 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Apr 11 |
| Scarlet sage | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 |
| Lantana | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 |
| Madagascar periwinkle | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 |
| Nasturtium | Plant outside: May 23 to Jun 27 | Plant outside: May 23 to Jun 27 |
| Sweet pea | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 |
| Larkspur | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 |
| Pot marigold | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 | Plant outside: Apr 18 to May 16 Fall planting: Aug 7 to Sep 4 |
| Coleus | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 14 |
| Garden verbena | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 |
| Spider flower | Plant outside: May 23 to Jun 27 | Plant outside: May 23 to Jun 27 |
| Floss flower | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 | Plant outside: May 23 to Jun 27 Start seeds indoors: around Mar 28 |
| Moss rose | Plant outside: May 23 to Jun 27 | Plant outside: May 23 to Jun 27 |
Zones measure winter cold, not season length, so your own frost dates can be a week or two off the zone median. Look up your frost dates by ZIP code, or read all about zone 3b.
Hardiness ranges, light and size are typical figures from university extension services and botanic garden plant records; a named variety can differ, so check its tag. Planting dates come from each zone's median frost dates (NOAA 1991 to 2020 climate normals) and the timing rules in how we check.