Portulaca (Moss Rose) in Zone 6a & 6b
Portulaca grandiflora
Yes, portulaca (moss rose) grows in zones 6a and 6b. Start seeds indoors Mar 7–Mar 14 and plant out May 2–May 9.
When to plant portulaca (moss rose) in zone 6b
Zones 6a and 6b share the same average frost dates, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Either works.
| Start indoors | Mar 7–Mar 14 |
|---|---|
| Direct sow / transplant outside | May 2–May 9 |
| Estimated bloom | Jul 1–Jul 8 (~60 days after planting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 4-8 in.
Plant alongside it in zone 6b
These go outside within two weeks of portulaca (moss rose) in zone 6b, so one planting day can cover them.
- NasturtiumMay 2–May 9
- MarigoldMay 2–May 9
- Ageratum (Flossflower)May 2–May 9
- Annual Geranium (Pelargonium)May 2–May 9
- Butterfly Weed (Asclepias)May 2–May 9
- Campanula (Bellflower)May 2–May 9
Portulaca (moss rose) is native to hot, dry plains in South America, and it shows: this is a good summer annual for the driest, sunniest, most neglected corner of the garden, not a plant that needs coddling. It forms a succulent, 4- to 8-inch mat studded with rose-like or single cup blooms in bright pink, orange, yellow, red, or white.
How portulaca (moss rose) fits zone 6's season
Zone 6b's frost-free window runs about 173 days, from April 25 to October 15. Portulaca (moss rose) needs about 60 days from sowing to first bloom.
Portulaca (Moss Rose) planting windows in every zone
Zone 6b 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 | Apr 1–Apr 8 | May 27–Jun 3 | Jul 26–Aug 2 |
| 3a & 3b | Apr 11–Apr 18 | Jun 6–Jun 13 | Aug 5–Aug 12 |
| 4a & 4b | Mar 27–Apr 3 | May 22–May 29 | Jul 21–Jul 28 |
| 5a & 5b | Mar 22–Mar 29 | May 17–May 24 | Jul 16–Jul 23 |
| 6a & 6b (your zone) | Mar 7–Mar 14 | May 2–May 9 | Jul 1–Jul 8 |
| 7a & 7b | Feb 20–Feb 27 | Apr 17–Apr 24 | Jun 16–Jun 23 |
| 8a & 8b | Feb 4–Feb 11 | Apr 1–Apr 8 | May 31–Jun 7 |
| 9a & 9b | Dec 28–Jan 4 | Feb 22–Mar 1 | Apr 23–Apr 30 |
| 10a & 10bSpring window | Jan–Apr | Mar–Jun | ~60 days after transplanting |
| 11a & 11b | Nov 13–Nov 20 | Jan 8–Jan 15 | Mar 9–Mar 16 |
Bloom dates are about 60 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 portulaca (moss rose).
Where to buy portulaca seeds
True Leaf Market · Burpee (each supplier's portulaca seeds)
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing portulaca (moss rose)" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 6b calendar · Plan your beds in the Garden Designer →
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Growing Portulaca (Moss Rose) in USDA zone 6b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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