Gomphrena (Globe Amaranth) in Zone 10a & 10b

Gomphrena globosa

Yes, gomphrena (globe amaranth) grows in zones 10a and 10b. Start seeds indoors in Jan–May and plant out in Mar–Jul.

When to plant gomphrena (globe amaranth) in zone 10b

Zones 10a and 10b 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.

Window	Spring window
Start indoors	Jan–May
Direct sow / transplant outside	Mar–Jul
Estimated bloom	~90 days after transplanting

Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1-2 ft.

Zone 10b dates sourced from growinginthegarden.com.

Full gomphrena (globe amaranth) profile · Companion planting guide · Zone 10b planting calendar

Plant alongside it in zone 10b

These go outside within two weeks of gomphrena (globe amaranth) in zone 10b, so one planting day can cover them.

Gomphrena (globe amaranth) grows a long taproot that gives it above-average drought tolerance once established, and it rewards that patience with one of the longest bloom windows of any flower on this list: April through October in a lot of climates. What look like its "flowers" are papery bracts, not petals, which is why cut stems hung upside down hold their color and shape for months in a dried arrangement instead of shattering the way true petals do.

How gomphrena (globe amaranth) fits zone 10's season

Zone 10b's frost-free window runs about 324 days, from January 30 to December 20. Gomphrena (globe amaranth) needs about 90 days from transplant to first bloom.

Gomphrena (Globe Amaranth) planting windows in every zone

Zone 10b 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	Aug 25–Sep 1
3a & 3b	Apr 11–Apr 18	Jun 6–Jun 13	Sep 4–Sep 11
4a & 4b	Mar 27–Apr 3	May 22–May 29	Aug 20–Aug 27
5a & 5b	Mar 22–Mar 29	May 17–May 24	Aug 15–Aug 22
6a & 6b	Mar 7–Mar 14	May 2–May 9	Jul 31–Aug 7
7a & 7b	Feb 20–Feb 27	Apr 17–Apr 24	Jul 16–Jul 23
8a & 8b	Feb 4–Feb 11	Apr 1–Apr 8	Jun 30–Jul 7
9a & 9b	Dec 28–Jan 4	Feb 22–Mar 1	May 23–May 30
10a & 10bSpring window (your zone)	Jan–May	Mar–Jul	~90 days after transplanting
11a & 11b	Nov 13–Nov 20	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 gomphrena (globe amaranth).

Where to buy gomphrena seeds

Botanical Interests · True Leaf Market · Burpee (each supplier's gomphrena seeds)

Varieties we recommend, and where to get them:

Fireworks: NC State Extension's Plant Toolbox describes it as an amaranth with incredible drought and heat tolerance and a long bloom season, growing 3-4 feet tall, taller than most gomphrena, so plan for it at the back of a bed rather than the front. Buy: Burpee Full notes

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See it growing

Search YouTube for "growing gomphrena (globe amaranth)" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)

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Growing Gomphrena (Globe Amaranth) in USDA zone 10b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.

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