Knowing when to plant in Pennsylvania is the single most important factor for a successful garden. This guide will walk you through the best planting times for vegetables, flowers, and more across the state’s varied climate.
Pennsylvania’s gardening zones range from 5b to 7b, meaning frost dates can shift by several weeks. Your local conditions are key. Always check your specific last spring frost date and first fall frost date for the most accurate schedule.
When to Plant in Pennsylvania – Best Planting Times for
Your planting calendar in PA breaks down into two main seasons: the cool spring period and the warm summer season. Some plants thrive in the fall, too, offering a third harvest or bloom period.
Understanding Pennsylvania’s Growing Zones
First, find your USDA Hardiness Zone. This number tells you the average coldest winter temperature in your area. You can find it with a quick online search using your zip code.
- Zone 5b (-15°F to -10°F): Northern tier and high elevations. Shorter growing season.
- Zone 6a (-10°F to -5°F): Much of central and northeastern PA.
- Zone 6b (-5°F to 0°F): South-central regions and parts of the east.
- Zone 7a (0°F to 5°F): Southeastern corners, including Philadelphia.
These zones help you choose perennial plants that will survive your winters. For annual vegetables and flowers, frost dates matter more.
Spring Planting Guide (Cool-Season Crops)
As soon as the ground is workable in spring, you can start. Cool-season crops tolerate light frost and prefer cooler soil temperatures.
Early Spring (2-4 Weeks Before Last Frost)
You can directly sow these seeds into your garden soil. The soil is often still cool and wet, so well-drained beds are essential.
- Peas
- Spinach
- Kale
- Radishes
- Carrots
- Lettuce
Mid-Spring (On or After Last Frost Date)
This is the classic “planting time” for many gardeners. The risk of a hard frost has passed for most areas. You can now plant seedlings you started indoors.
- Broccoli transplants
- Cabbage transplants
- Onion sets
- Potatoes (seed pieces)
- Swiss chard
For flowers, this is the time to plant hardy annuals like pansies and sweet peas. You can also sow seeds for poppies and larkspur directly.
Summer Planting Guide (Warm-Season Crops)
Wait until all danger of frost is gone and the soil has warmed up significantly. These plants will not tolerate cold and need warm nights to grow properly.
Late Spring to Early Summer
This usually means late May for zone 6 and early June for zone 5. Don’t rush it—cold soil can stunt growth for the entire season.
- Tomatoes (transplants)
- Peppers (transplants)
- Eggplant (transplants)
- Cucumbers (seeds or transplants)
- Beans (seeds)
- Squash and Zucchini (seeds)
This is also the time to plant tender annual flowers like marigolds, zinnias, and impatiens. Your local garden center will be full of these after the frost date passes.
Fall Planting Guide (Second Season)
Many gardeners miss the opportunity for a fall garden. You can plant cool-season crops again in late summer for a autumn harvest. The flavors are often sweeter after a light frost.
Midsummer to Late Summer
Count backwards from your first fall frost date. For example, to grow broccoli, find its “days to maturity” on the seed packet and plant it so it matures before that first hard frost.
- Lettuce (sow every 2 weeks for continuous harvest)
- Spinach
- Kale
- Radishes
- Beets
- Turnips
You can also plant spring-flowering bulbs like tulips and daffodils in the fall, usually around October. This gives them the cold period they need to bloom.
Regional Adjustments Across Pennsylvania
A one-size-fits-all schedule doesn’t work here. The state’s geography creates microclimates.
- Western & Northern PA (Zones 5b-6a): Frosts come earlier in fall and linger later in spring. Start warm-season crops indoors and use season extenders like cold frames.
- Central & Ridge-and-Valley (Zone 6): This is the “average” PA schedule. Follow standard frost date guidelines closely.
- Southeastern PA (Zones 6b-7a): Longer growing season. You can often plant warm-season crops a week or two earlier and get a longer fall harvest window.
Always talk to neighboring gardeners or your county’s Penn State Extension office. They have hyper-local knowledge that’s invaluable.
Step-by-Step: Creating Your Personal Planting Calendar
- Find Your Frost Dates: Search “[Your Town, PA] last spring frost date” and first fall frost date. Write them down.
- List Your Plants: Write down everything you want to grow this year.
- Check Seed Packets: Note each plant’s “days to maturity” and whether it’s a cool-season or warm-season crop.
- Plot Spring Dates: For transplants, work backwards 6-8 weeks from your planting date to know when to start seeds indoors.
- Plot Fall Dates: For fall crops, work backwards from your first fall frost date using the “days to maturity” plus a 2-week “harvest period” buffer.
Keeping a simple garden journal from year to year is the best way to refine your own perfect schedule. Note what worked and what didn’t.
Common Planting Mistakes to Avoid
Even experienced gardeners make a few errors. Here’s how to sidestep the most common ones.
- Planting Too Early: Eagerness leads to frozen seedlings. Warm soil is better than early planting for summer crops.
- Ignoring Soil Temperature: A soil thermometer is a cheap, useful tool. Peas need 45°F soil, but peppers need 60°F+.
- Crowding Plants: Follow spacing on seed packets. Good air flow prevents disease and gives plants room to grow to full size.
- Forgetting Succession Planting: Don’t plant all your lettuce at once. Sow small amounts every two weeks for a continuous supply instead of a giant glut.
FAQ: Pennsylvania Planting Times
When is the best time to plant tomatoes in PA?
Plant tomato transplants outdoors 1-2 weeks after your last spring frost date, when night temperatures stay above 50°F consistently.
What can I plant in April in Pennsylvania?
In April, you can direct sow peas, spinach, radishes, carrots, and beets. You can also plant potatoes and onion sets. Towards the end of the month in warmer zones, you might plant broccoli or cabbage transplants.
When should I plant perennials in Pennsylvania?
The ideal times are early spring (as soon as the ground thaws) or early fall (September to early October). This gives the plants time to establish roots before summer heat or winter cold sets in.
How late can you plant a garden in PA?
For a fall harvest, you can plant quick-growing crops like lettuce and radishes up until about 6-8 weeks before your first fall frost. For spring, it’s never too late—just choose crops with a short maturity date if you start in June or July.
When do you plant bulbs in Pennsylvania?
Plant spring-flowering bulbs like tulips, daffodils, and crocus in the fall, typically from late September through October, before the ground freezes. The soil should be cool.
Gardening in Pennsylvania is a rewarding journey through the seasons. By paying close attention to timing and your local conditions, you’ll set your plants up for a healthy and productive life. Your efforts will be rewarded with fresh food and beautiful blooms from spring straight through to fall.