Idaho · zones 5b–7b
When to plant snap peas in Idaho.
Sow between Mar 20 to May 1 in a typical year, keyed to Idaho's median last frost around May 11. A second, fall sowing fits Jul 6 to Jul 14. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Snap Peas dates for a typical Idaho season.
Direct sow
Mar 20 to May 1
Keyed to the ~May 11 last frost. Sow 1" deep, 2" apart.
Fall round
Jul 6 to Jul 14
Counted back from the ~Sep 28 first frost.
Harvest
~62 days later
~0.4 lb per plant over ~3 weeks.
Idaho spans more than one climate: Zone 6 is the most common zone, but the state runs 5b to 7b. 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.
Idaho growing notes
Snap peas run both ends of the Idaho season and sit out the hot middle, which is why eight separate sowings do more here than one long planting ever could.
Two windows bookending the heat, not one long season
Snap peas work the cold shoulders of the season rather than running through the middle of it: an early sowing goes into soil while it is still cool, and a second is timed backward from the season's first fall frost to finish before cold shuts it down, with the hot stretch between the two skipped outright, since pod quality drops hard once real heat sets in. Seed goes in direct, about 1 inch deep and packed close, roughly 2 inches apart down the row, reaching harvest in about 62 days, quick enough that both windows have room for more than one sowing apiece.
That is the logic behind eight separate sowings rather than one: each planting has a fairly short run of good picking before the pods toughen, so spacing sowings a couple of weeks apart through each window keeps a steady supply coming instead of one big harvest followed by a long gap. At around 0.4 pound per plant, a single sowing is modest on its own, but eight rounds across the two windows add up to real volume over a season without asking for much bed width at any one time.
A trellis earns its keep twice over
Pea seed is large, and pressed into ground that is still cold and waterlogged, it rots before it sprouts more often than seed sown into soil that is merely cool. Peas tolerate cool soil at sowing far better than they tolerate wet soil, worth checking with a bare hand before the earliest sowing goes in rather than going strictly by how early the calendar allows.
A vine trained up a trellis or fence, rather than left to sprawl over itself on the ground, gets air moving through the foliage in a way a tangled pile never does, and that airflow accounts for most of the difference between a planting that shrugs off powdery mildew and one that does not. Support pays for itself twice, once in picking ease and again in disease that never gets the still, damp air it needs to take hold.
Two pests instead of the usual longer list
This crop's most common problems here are pea aphid and powdery mildew. Pea aphid clusters on new growth and pods, worse in a mild spring before predator insects have built up numbers, and it usually falls off on its own as ladybugs and lacewings catch up through the season. Powdery mildew favors the humid, cooler-night stretch that a late spring sowing or an early fall sowing runs into, which happens to be exactly the sowings on either side of the hot gap in the middle.
That makes the last spring round and the first fall round the two worth checking most closely, rather than treating all eight the same. Between those two, most of what decides a good picking here comes down to timing the eight sowings well and giving the vines something to climb, not to spraying anything.
In Idaho: watch for
The pests that find snap peas here.
The short season here, about 140 frost-free days, keeps snap pea in front of pea aphid only briefly. One early row cover usually carries a planting through the worst of it.
Clusters on the tender growing tips where new tendrils form.
Organic fix: Knock colonies loose with a firm blast from the hose before they build.
White powder on leaves after warm dry days and cool, dewy nights.
Organic fix: Grow resistant varieties and trellis so vines are not lying on each other.
Root rot
Seedlings stall and yellow from the bottom up, and a lifted plant shows soft brown roots instead of firm white ones.
Organic fix: Sow into a raised or well-drained bed, work compost into heavy ground, ease off the water, and move peas to fresh ground next year.
Your season math: Idaho gives snap peas about 140 frost-free days, and it needs roughly 62 days to a first harvest. That fits about 8 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting snap peas in Idaho: questions
When should I plant snap peas in Idaho?+
In a typical Idaho year, sow snap peas between Mar 20 to May 1, keyed to the state's median last frost around May 11. There's also a fall window: Jul 6 to Jul 14. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Idaho?+
Idaho spans zones 5b–7b, mostly zone 6. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many snap peas 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.