When to plant sweet corn in Pennsylvania
Pennsylvania’s average last spring frost is May 1, and the first fall frost typically arrives around October 10 — about 162 frost-free days (USDA zones 5a, 5b, 6a, 6b, 7a, 7b). Sweet Corn needs 60–100 days to mature, which fits comfortably within Pennsylvania's growing season.
Pennsylvania covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant sweet corn in Pennsylvania: the short answer
For a spring planting, sow May 3 – May 22. Wait until the soil is at least 55°F and frost is over.
Succession sow again in Pennsylvania: May 22 · Jun 5 · Jun 19 · Jul 3 · Jul 17
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow sweet corn in Pennsylvania, step by step
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 24 inches deep, with a pH between 5.8 and 7.0. Dig in compost before planting.
- Sow outdoors (May 3 – May 22). Space plants about 10 inches apart in rows 30 inches apart, sowing seed 1.5 inches deep. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. It needs plenty of water; keep the soil evenly moist and never let it dry out.
- Watch for pests and problems. Pests: corn earworm, European corn borer, corn rootworm, raccoons. Diseases and disorders: common smut, common rust, Stewart's wilt.
- Harvest (from about Jul 7 – Aug 16). Sweet Corn takes 60-100 days to reach harvest. Plant in a block of at least 4 short rows, not one long row, or the ears fill unevenly. Keep sugar-enhanced and supersweet types isolated from field corn. Succeed by sowing every 2 weeks or planting early/mid/late varieties together.
Figures come from our crop data; dates use Pennsylvania’s average frost dates. More in the full sweet corn growing guide.
Sweet Corn planting dates by USDA zone in Pennsylvania
Pennsylvania spans USDA zones 5a, 5b, 6a, 6b, 7a, 7b. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the sweet corn dates shift with them.
When to plant sweet corn in nearby states
| State | Last frost | Sow |
|---|---|---|
| Pennsylvania (this page) | May 1 | May 3 – May 22 |
| New Jersey | April 20 | Apr 22 – May 11 |
| Delaware | April 14 | Apr 16 – May 5 |
| Maryland | April 14 | Apr 16 – May 5 |
| District of Columbia | April 10 | Apr 12 – May 1 |
| Virginia | April 15 | Apr 17 – May 6 |
| West Virginia | May 5 | May 7 – May 26 |
Questions gardeners in Pennsylvania ask
When is the best time to plant sweet corn in Pennsylvania?
Sow sweet corn in Pennsylvania between May 3 and May 22. That timing is set by Pennsylvania's average last spring frost of May 1; Pennsylvania spans several climates, so cooler and higher parts of the state run later.
What is the latest I can plant sweet corn in Pennsylvania?
About August 11. Sweet corn needs at least 60 days to mature, and frost around October 10 ends the season, so later plantings risk being cut short.
When will sweet corn planted in Pennsylvania be ready to harvest?
Planted on time, sweet corn is usually ready from about July 7 to August 16, 60-100 days after sowing.
When is the last frost in Pennsylvania?
On average around May 1, with the first fall frost around October 10 - about 162 frost-free days. Your town may differ by two weeks or more.