When to plant Zinnia in Zone 4a
In Zone 4a, Zinnia: start seeds indoors around Apr 17–May 1; transplant outdoors around May 22–May 29; direct sow outdoors around May 15–May 29. Expect to harvest around Jul 14–Jul 28.
| Step | When |
|---|---|
| Start seeds indoors | Apr 17 – May 1 |
| Transplant outdoors | May 22 – May 29 |
| Direct sow outdoors | May 15 – May 29 |
| Harvest | Jul 14 – Jul 28 |
| Harvest | Jul 21 – Jul 28 |
Tip: A cut-flower workhorse. Direct-sow after frost and pinch young plants for more stems.
Zone 4a averages a last spring frost around May 15 and a first fall frost around Sep 18. These are zone averages — look up your ZIP for your exact area.
See the full Zone 4a calendar in the tool →