Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 00636 — Rosario, PR

ZIP code 00636 (Rosario, San German County) is in USDA zone 12b: the coldest winter night averages 55 to 60 °F.

Where ZIP 00636 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not 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.

Zone12b55 to 60 °F
Coldest night12.8 to 15.6 °C
Last frostrare
First frostrare
2012 zone—

The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 12b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Rosario, PR…

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

Frost is rare or absent here: Rosario, PR is in zone 12b, where the coldest night of a typical winter stays above freezing. Cool-season vegetables grow best from fall through spring; summer heat, not frost, is the limit.

Native plants for zone 12b in Puerto Rico

153 plants native to Puerto Rico, recorded in Puerto Rico, and rated by the USDA to survive 55 °F or colder — the bottom of zone 12b. Each links to its USDA PLANTS profile.

Trees 41

achiotillo52 ft · blooms early spring · high shade tolerance · to 40 °Fbastard redwood15 ft · to 40 °Fbulletwood100 ft · blooms summer · low shade tolerance · to 52 °Fbullwood100 ft · blooms summer · high shade tolerance · to 40 °Fcabbagebark tree90 ft · blooms summer · high shade tolerance · to 32 °Fcandletree115 ft · blooms early summer · medium shade tolerance · to 50 °F

Shrubs 46

American muskwood10 ft · blooms spring · to 40 °FAntilles calophyllum65 ft · blooms late spring · medium shade tolerance · to 36 °Fbastard stopper43 ft · blooms summer · high shade tolerance · to 40 °Fblack mangrove30 ft · blooms indeterminate · high shade tolerance · to 10 °Fbroadleaf caper33 ft · to 40 °Fbroomstick25 ft · blooms spring · medium shade tolerance · to 40 °F

Wildflowers & perennials 31

bayhops1 ft · blooms indeterminate · medium shade tolerance · to 17 °Fbroadleaf arrowhead5 ft · blooms late spring · high shade tolerance · to −33 °FCanadian horseweed5 ft · blooms indeterminate · high shade tolerance · to 52 °Fcinnamon fern5 ft · blooms spring · low shade tolerance · to −33 °Fclimbing dayflower1 ft · blooms summer · low shade tolerance · to 47 °Fcommon duckmeatblooms late summer · medium shade tolerance · to −38 °F

Grasses 34

American cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °Fbroadleaf carpetgrass1 ft · blooms spring · high shade tolerance · to −3 °Fbroomsedge bluestem3 ft · blooms late spring · high shade tolerance · to −18 °Fbrownseed paspalum3 ft · blooms summer · medium shade tolerance · to 7 °Fbushy bluestem6 ft · blooms late summer · high shade tolerance · to −23 °F

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 Rosario, PR.

Soil in Rosario, PR

The soil mapped at the center of ZIP 00636 is Humatas — clay, well drained.

TextureClayholds water and nutrients; slow to drain and warm up
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter5.7%high
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Humatas clay, 12 to 20 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 00636; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Rosario, PR

Longest day13 h 13 mindaylight on June 21
Shortest day11 h 02 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

0066012b
Hormigueros, PR · 3 mi
0068012b
Mayaguez, PR · 4 mi
0068113a
Mayaguez, PR · 5 mi
0068312b
San German, PR · 5 mi
0068213a
Mayaguez, PR · 6 mi
0062312b
Cabo Rojo, PR · 8 mi
0067012b
Las Marias, PR · 8 mi
0061012b
Anasco, PR · 10 mi

Puerto Rico planting zones →

Questions about 00636

What planting zone is ZIP code 00636?

ZIP code 00636 (Rosario, PR) is in USDA hardiness zone 12b on the 2023 map: the coldest night of an average winter reaches 55 to 60 °F (12.8 to 15.6 °C).

What kind of soil does 00636 have?

The USDA soil survey maps Humatas at the center of ZIP 00636: clay, well drained, pH about 5.5 (moderately acidic).

What kind of onions grow in Rosario, PR?

Short-day onions: the longest day near 00636 is 13 h 13 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.