Wyoming · zones 4a–5a
When to plant spinach in Wyoming.
Sow between Apr 6 to May 18 in a typical year, keyed to Wyoming's median last frost around May 28. A second, fall sowing fits Jul 4 to Aug 22. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Spinach dates for a typical Wyoming season.
Direct sow
Apr 6 to May 18
Keyed to the ~May 28 last frost. Sow 0.5" deep, 3" apart.
Fall round
Jul 4 to Aug 22
Counted back from the ~Sep 17 first frost.
Harvest
~42 days later
~0.25 lb per plant over ~1 weeks.
Wyoming spans more than one climate: Zone 5 is the most common zone, but the state runs 4a to 5a. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
In Wyoming: watch for
The pests that find spinach here.
The short season here, about 112 frost-free days, keeps spinach in front of leaf miners only briefly. One early row cover usually carries a planting through the worst of it.
Winding pale tunnels or blotches inside the leaves.
Organic fix: Pick and destroy mined leaves; cover the row.
Cercospora leaf spot
Round spots with gray centers and a red-purple rim, oldest leaves worst.
Organic fix: Space wider so leaves dry fast, clear old debris, and pull pigweed and lambsquarters nearby.
Your season math: Wyoming gives spinach about 112 frost-free days, and it needs roughly 42 days to a first harvest. That fits about 11 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting spinach in Wyoming: questions
When should I plant spinach in Wyoming?+
In a typical Wyoming year, sow spinach between Apr 6 to May 18, keyed to the state's median last frost around May 28. There's also a fall window: Jul 4 to Aug 22. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Wyoming?+
Wyoming spans zones 4a–5a, mostly zone 5. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many spinach plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.