When to plant hydrangeas
Plant hydrangeas from the last spring frost to 2 weeks after it in spring, or 6–8 weeks before the first fall frost for a fall crop. That works out to zone 5b (early May to mid May), zone 7a (mid April to late April) and zone 9a (early March to mid March).
Hydrangeas planting dates by zone
| Zone | Spring | Fall |
|---|---|---|
| 4a | May 15 – May 29 | Aug 1 – Aug 15 |
| 4b | May 13 – May 27 | Aug 4 – Aug 18 |
| 5a | May 11 – May 25 | Aug 6 – Aug 20 |
| 5b | May 5 – May 19 | Aug 13 – Aug 27 |
| 6a | Apr 30 – May 14 | Aug 20 – Sep 3 |
| 6b | Apr 24 – May 8 | Aug 24 – Sep 7 |
| 7a | Apr 15 – Apr 29 | Aug 30 – Sep 13 |
| 7b | Apr 6 – Apr 20 | Sep 6 – Sep 20 |
| 8a | Mar 27 – Apr 10 | Sep 12 – Sep 26 |
| 8b | Mar 16 – Mar 30 | Sep 20 – Oct 4 |
| 9a | Mar 2 – Mar 16 | Oct 1 – Oct 15 |
| 9b | Feb 4 – Feb 18 | Oct 15 – Oct 29 |
How to plant hydrangeas
| Plant as | potted shrubs |
|---|---|
| Depth | Same depth as the pot |
| Spacing | 3–10 ft |
| Light | Morning sun, afternoon shade |
| Time to bloom | 1–2 years |
| Hardiness | Perennial in zones 3–9 depending on species |
Early fall planting lets roots grow in cool weather without summer heat stress.
Bigleaf hydrangea flower color depends on soil pH: acidic soil gives blue, alkaline gives pink.
Water deeply the first summer.
Panicle hydrangeas (Hydrangea paniculata) tolerate more sun and cold than bigleaf types and bloom on new wood every year.
Smooth hydrangeas such as 'Annabelle' can be cut to the ground in late winter and still flower that summer.
A 2–3 inch layer of mulch keeps the shallow roots cool and moist.
When to expect flowers from hydrangeas
Cut blooms for drying when they feel papery. Prune by type: bigleaf hydrangeas bloom on old wood, panicle types on new wood.
Exact dates for your town: planting calendar · frost dates by state.
More flowers to plant
Begonias · Coleus · Marigolds · Zinnias · Sunflowers · Cosmos · Mums · Lantana