Indianapolis (46204) — USDA Zone 6a

Frost dates and growing season for 46204

These are 50%-probability averages modeled from this ZIP's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by April 22, but in a colder-than-average year it can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.

Growing season in Indianapolis

Indianapolis, Indiana sits in USDA Zone 6a, with roughly 179 frost-free days between an average last spring frost around April 22 and a first fall frost around October 18. That is a standard temperate season — most common vegetables finish comfortably, and a single main planting plus one succession round works well. Indianapolis lies near 39.8°N; higher-latitude gardens get longer midsummer days but a tighter shoulder season at this zone. As a large metro, the built-up core here typically runs up to half a zone warmer than outlying suburbs through the urban heat-island effect — sheltered city gardens often push tender crops a little earlier than the ZIP average suggests.

What grows in Indianapolis

Indianapolis falls in USDA Zone 6a, which means the same hardiness constraints apply as the full Zone 6 guide. Vegetables, herbs, and fruit trees rated to Zone 6a (or hardier) will overwinter here in a typical year.

• Tomatoes (all types)
• Peppers, eggplant
• Squash, melons, cucumbers
• Beans, peas
• Sweet corn
• Apples, pears, peaches, plums
• Cherries, blueberries
• Asparagus, rhubarb
• Garlic (fall-planted)
• Strawberries

What to plant in Indianapolis this week

Indianapolis's last frost is around April 22. This is the spring transplant window — start tomatoes and peppers indoors if you haven't, and direct-sow cold-tolerant crops now.

• When to plant tomatoes in zone 6
• When to plant peppers in zone 6
• When to plant basil in zone 6
• When to plant bush beans in zone 6
• When to plant cucumbers in zone 6

Full planting calendar for Indianapolis

Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 6 averages:

• When to plant tomatoes in zone 6
• When to plant peppers in zone 6
• When to plant basil in zone 6
• When to plant garlic in zone 6
• When to plant lettuce in zone 6
• When to plant bush beans in zone 6
• When to plant cucumbers in zone 6
• When to plant summer squash in zone 6
• When to plant peas in zone 6
• When to plant carrots in zone 6

Local microclimate notes

Zone tables give you the average — but Indianapolisgardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record (the last time you actually got frost damage) is more accurate than any national average.

Source and methodology

Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from this ZIP's USDA hardiness zone and regional NOAA 1991-2020 climate normals — they are zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations are drawn from US Cooperative Extension references and curated by the Growli editorial team. Last reviewed May 2026.

Nearby ZIP codes in Indiana

• 46802 — Fort Wayne (Zone 6a)
• 47708 — Evansville (Zone 7a)
• 46202 — Indianapolis (Downtown) (Zone 6b)
• 46219 — Indianapolis (Irvington) (Zone 6a)
• 46226 — Indianapolis (Northeast) (Zone 6a)
• 46032 — Carmel (Zone 6a)
• 46060 — Noblesville (Zone 6a)
• 46368 — Portage (Zone 6a)
• 46410 — Merrillville (Zone 6a)
• 46545 — Mishawaka (Zone 6a)
• 46601 — South Bend (Zone 6a)
• 47404 — Bloomington (Zone 6b)
• Browse all US ZIP codes by state

Related guides

• USDA Zone 6 — full plant + frost guide
• Look up another ZIP code
• Watering frequency calculator
• How to start a vegetable garden — beginner guide