Idaho · zones 5b–7b
When to plant cherry tomatoes in Idaho.
Sow or transplant between May 18 to Jul 18 in a typical year, keyed to Idaho's median last frost around May 11. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Cherry Tomatoes dates for a typical Idaho season.
1 · Start indoors
Apr 6 to Jun 6
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
May 18 to Jul 18
Keyed to the ~May 11 last frost. Sow 0.25" deep, 24" apart.
Harvest
~57 days later
~8 lb per plant over ~10 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
Cherry tomatoes finish in about 57 days from transplant here, and that gap below Idaho's 140-day season is the difference between a sure thing and a gamble.
Why the margin matters more than the size of the fruit
Frost to frost, growers across the state work with something like 140 days, and a cherry tomato only needs about 57 of them from transplant to start loading fruit, next to 73 for a full-size slicer grown the same way. That extra margin, something like 83 days of slack instead of 67, is why cherry types are the safer bet in the colder 5b and 6a pockets of the state: high mountain valleys and the cooler edges of the panhandle. A grower there who loses two or three weeks to a slow, cold spring still has room to finish this crop; the same slow start on a bigger-fruited tomato can eat the whole cushion.
The tradeoff shows up at harvest, not at planting. Both types go in as transplants at the same 24-inch spacing and the same shallow, quarter-inch sowing depth if starting seed indoors, and both deal with the same pests and diseases. What differs is how forgiving the finish line is. A gardener in the Treasure Valley's warmer ground can grow either type without much drama. A gardener working a short-season plot in the high country, or a damp panhandle yard, gets a real harvest from this crop in years a bigger slicer barely ripens before the first fall frost ends it.
Reading a stalled plant instead of guessing at a number
Cool nights slow fruit set on any tomato, and the tell isn't a temperature to chase down, it's the plant's own behavior. Heavy bloom with nothing sizing up behind it means the flowers aren't holding while nights run cold, not that the plant is sick or short on nutrients. Nothing fixes that faster than warmer nights arriving on their own, and feeding or spraying a stalled plant just wastes both. What a grower can actually do is give next year's earliest transplant the warmest spot available, a south wall, a raised bed, anywhere the ground holds heat overnight, and save the coldest corner of the yard for something that flowers less and shrugs off the chill.
Early blight, late blight, and septoria leaf spot all show up on this crop too, and all three need wet leaves to get moving. Idaho's dry air doesn't supply that wetness on its own the way a humid state's air does; a sprinkler running at night or plants crowded too close usually does the supplying instead. Water at the soil line rather than overhead, and the disease pressure most growers deal with here is one they can mostly choose not to create in the first place.
Hornworms matter more than aphids on a plant this size
A tomato hornworm does more visible damage to a compact cherry plant than to a sprawling slicer, since it can strip a branch carrying a dozen small trusses rather than three or four big fruit. The caterpillar itself is nearly invisible against the foliage; the dark droppings it leaves on leaves and on the ground below a stripped stem are not. Check any caterpillar found before removing it: small white cocoons fixed to its back mean a parasitic wasp is already inside, and that hornworm is more useful left in place, finishing its own life cycle and sending more wasps after the next one.
Aphids matter less here than the hornworm does, but they still cluster on new growth and leaf undersides where they're easy to miss. A hard spray of water handles a light infestation without needing anything else. With roughly 8 pounds of fruit per plant across a season at that 24-inch spacing, three or four plants already covers most households for fresh eating, worth remembering before doubling a planting just to hedge against pests; a couple of well-tended plants beats a crowded row that struggles for airflow.
In Idaho: watch for
The pests that find cherry tomatoes here.
The short season here, about 140 frost-free days, keeps tomato, cherry in front of tomato hornworm only briefly. One early row cover usually carries a planting through the worst of it.
Big green caterpillars strip leaves and leave black droppings.
Organic fix: Handpick at dusk; spray Bt on the young ones.
Clusters on new growth, sticky leaves, curling tips.
Organic fix: Blast with water, then insecticidal soap or neem.
Dark spots with concentric rings, starting on the lowest, oldest leaves.
Organic fix: Remove affected leaves, mulch to stop soil splash, space for airflow.
Greasy, water-soaked blotches in cool, wet spells. No rings, and not bottom-up.
Organic fix: Pull infected plants fast, keep leaves dry, use neem as a preventive.
Septoria leaf spot
Many small tan spots with dark brown edges, low leaves first, no rings inside.
Organic fix: Strip the lowest leaves, mulch against soil splash, stake for airflow.
Your season math: Idaho gives cherry tomatoes about 140 frost-free days, and it needs roughly 57 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting cherry tomatoes in Idaho: questions
When should I plant cherry tomatoes in Idaho?+
In a typical Idaho year, sow cherry tomatoes or set out transplants between May 18 to Jul 18, keyed to the state's median last frost around May 11. Your exact dates shift with your ZIP code and microclimate.
When do I start cherry tomatoes seeds indoors in Idaho?+
Start seeds inside about 6 weeks before set-out: roughly Apr 6 to Jun 6 for a typical Idaho season.
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 cherry tomatoes 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.