Showy Evening Primrose in Zone 5a & 5b

Oenothera speciosa

When to plant showy evening primrose in zone 5b

Zones 5a and 5b share the same average frost dates in our data, so this page covers both.

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

Start indoors	Not typically started indoors
Direct sow / transplant outside	May 10–May 17
Estimated bloom	May 9 '28–May 16 '28 (First real harvest the season after planting)

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

Showy evening primrose is the most aggressive plant in this dataset, and the extension source says so directly rather than hinting at it.

How showy evening primrose fits zone 5's season

Zone 5b's frost-free window runs about 148 days, from May 10 to October 5. Showy Evening Primrose takes about 1 growing season to reach full flowering, so what matters here is how many of these seasons it gets, not whether one is long enough.

Showy Evening Primrose is hardy in zones 5-8, so in zone 5b it stays in the ground through winter and comes back rather than being replanted. Allow about 2 ft of spread at maturity.

Good companions

No standout companions recorded yet for Showy Evening Primrose.

Where to buy showy evening primrose seeds

See why we recommend these suppliers →

As an Amazon Associate we earn from qualifying purchases. Some links on this page also go to other retailers we may earn a commission from as an affiliate, at no extra cost to you. We only recommend products with a genuine consensus of positive, independent reviews. See the sources cited on each item.