Planting zone for 46143 — Greenwood, IN
ZIP code 46143 (Greenwood, Johnson County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 20 and the first fall frost October 21.
Where ZIP 46143 is
Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoomNot the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.
Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →
Frost forecast — next 7 nights
live from the National Weather ServiceLoading the forecast for Greenwood, IN…
Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.
Frost dates in Greenwood, IN
A hard freeze (28 °F) usually ends around April 7 and returns around November 1.
From the NOAA station Indianapolis Se Side, IN — 9 miles away, elevation 846 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.
When to plant vegetables in 46143
Counted from the median last spring frost (Apr 20) and first fall frost (Oct 21) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.
When spring arrived in 2026
In 2026, spring leaf-out near 46143 came on Mar 10 — 15 days earlier than the 1991–2020 average (Mar 25).
Mar 252026
Mar 10
The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).
Native plants for zone 6a in Indiana
558 plants native to the lower 48 states, recorded in Indiana, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.
Trees 71
Shrubs 105
Wildflowers & perennials 200
Grasses 161
Vines 9
Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Greenwood, IN.
Soil in Greenwood, IN
The soil mapped at the center of ZIP 46143 is Rensselaer — silty clay loam, poorly drained.
Map unit: Rensselaer silty clay loam-Urban land complex, 0 to 2 percent slopes.
Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 46143; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Greenwood, IN
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Indianapolis Se Side, IN (9 mi away); precipitation: Greenwood 4.6 Sw, IN (4 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
4 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.
Questions about 46143
What planting zone is ZIP code 46143?
ZIP code 46143 (Greenwood, IN) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).
When is the last frost in Greenwood, IN?
The median last spring frost (32 °F) near 46143 is April 20; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Indianapolis Se Side station.
When is the first frost in Greenwood, IN?
The median first fall frost near 46143 is October 21, giving a median frost-free growing season of 183 days.
When should I plant tomatoes in 46143?
Start tomato seeds indoors around Feb 23 – Mar 9 and set transplants outside around Apr 27 – May 11, one to three weeks after the median last frost.
How much rain and snow does 46143 get?
About 46.7 inches of precipitation a year (NOAA 1991–2020 normals, Greenwood 4.6 Sw station).
How hot do summers get in Greenwood, IN?
The average high peaks at 84 °F in July, with about 13 days a year at 90 °F or more.
What kind of soil does 46143 have?
The USDA soil survey maps Rensselaer at the center of ZIP 46143: silty clay loam, poorly drained, pH about 6.7 (neutral).
Did spring come early in Greenwood, IN in 2026?
Spring leaf-out near 46143 came on Mar 10 in 2026, 15 days earlier than the 1991–2020 average (Mar 25), according to the USA National Phenology Network Spring Index.
What kind of onions grow in Greenwood, IN?
Intermediate onions: the longest day near 46143 is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.