Pennyroyal in Zone 9a & 9b

Mentha pulegium

When to plant pennyroyal in zone 9b

Zones 9a and 9b share the same average frost dates in our data, so this page covers both.

Method: Direct sow: Direct-sow outside. Pennyroyal doesn't transplant well, or doesn't need the extra time indoors.

Start indoors	Not typically started indoors
Direct sow / transplant outside	Feb 15–Feb 22
Estimated harvest	Feb 15 '28–Feb 22 '28 (First real harvest the season after planting)

Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 0.5-1 ft.

Pennyroyal is a mint, it smells wonderful, and it is the one herb in this dataset that comes with a serious health warning.

How pennyroyal fits zone 9's season

Zone 9b's frost-free window runs about 293 days, from February 15 to December 5. Pennyroyal takes about 1 growing season to reach first worthwhile harvest, so what matters here is how many of these seasons it gets, not whether one is long enough.

Pennyroyal is hardy in zones 6-9, so in zone 9b it stays in the ground through winter and comes back rather than being replanted. Allow about 3 ft of spread at maturity.

Good companions

No standout companions recorded yet for Pennyroyal.

Where to buy pennyroyal seeds

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