The best time to plant corn in Pennsylvania is when the soil temperature at a 2-inch depth consistently reaches at least 50°F, especially in the cooler morning hours (6-7 am). This soil temperature threshold is critical for corn germination. Planting before this can damage the seed due to cold water imbibition, while planting too late affects yield negatively. Soil moisture should also be optimal, not too wet to avoid sidewall compaction. Additionally, the weather after planting should not have sustained freezing temperatures, as corn seedlings are susceptible to frost damage. Generally, corn planting in Pennsylvania begins:
- In southeastern Pennsylvania, from mid-April,
- In northern Pennsylvania, from late April to mid-May depending on the exact location and climate,
- Southern Pennsylvania farmers try to plant sweet corn from early to mid-April,
- Northern Pennsylvania plantings happen in mid- to late May.
Planting windows vary by region within Pennsylvania, with optimal periods stretching roughly April 15 to May 15 and sometimes later depending on local soil and climate conditions. Farmers often aim to plant corn about 10 to 14 days before the average date of the last killing frost in their area to maximize yield potential. In summary:
- Soil temperature at 2-inch depth should be ≥50°F in the early morning,
- Soil should pass a 'ball test' to confirm not too wet,
- Avoid planting if frost is forecast post-planting,
- General planting windows: mid-April (south) to mid-May (north),
- Sweet corn planting recommended early to mid-April in southern areas, mid- to late May in northern areas.
These guidelines help maximize germination, early growth, and ultimately corn yield in Pennsylvania.
