Growing in Pennsylvania: The Complete Planting Guide by Season

Pennsylvania’s growing season is more generous than most people think. Depending on where you are in the state, you’ve got roughly 150 to 200 frost-free days to work with — and if you plan around the shoulder seasons, you can stretch that even further.

I’ve been gardening in PA long enough to know that timing is everything here. A late frost in early May can wipe out tomato transplants you babied for weeks indoors. This guide breaks down what to plant and when, organized by season and adjusted for the real differences between Western, Central, and Eastern PA.

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Understanding Pennsylvania’s Growing Zones

Pennsylvania spans USDA hardiness zones 5a through 7a. You can look up your exact zone by zip code on the USDA Plant Hardiness Zone Map. That range matters more than most gardeners realize — a zone 5a garden in the Poconos plays by different rules than a zone 7a yard in Philadelphia.

Here’s how the zones break down by region:

These dates are averages based on NOAA climate normals — I’ve been caught by a late frost in early May more than once in Central PA, so don’t treat them as guarantees. A soil thermometer is a better indicator than the calendar — when your soil holds steady above 50°F, it’s generally safe to start planting warm-season crops.

Spring Planting (March–May)

Spring is when most of the action happens — and when most PA gardeners get a little too eager. I get it. That first warm week in March makes you want to plant everything. But the soil is still cold, and a frost can absolutely roll through well into April.

Early Spring: March

March is mostly about preparation and indoor starts. In Eastern PA (zone 7a), you can begin some direct sowing by late March. In Western PA and the mountains, March is still solidly winter gardening territory — meaning everything happens indoors or in cold frames.

Start indoors in March: – Tomatoes (6–8 weeks before last frost) – Peppers (8–10 weeks before last frost) – Broccoli and cabbage – Herbs: basil, parsley, cilantro

Direct sow outdoors (Eastern PA only, late March): – Peas – Spinach – Lettuce – Radishes

A decent grow light setup makes a real difference for indoor starts. Pennsylvania’s March daylight isn’t enough to keep seedlings from getting leggy, and a windowsill alone won’t cut it for tomatoes and peppers.

Mid-Spring: April

April is when Pennsylvania gardens come alive. By mid-April, most of Eastern and Central PA are past their last frost risk. Western PA gardeners should hold off on tender crops until late April or early May.

Direct sow outdoors across most of PA: – Carrots – Beets – Swiss chard – Kale – Potatoes (St. Patrick’s Day is the traditional planting date, but soil temperature matters more than tradition) – Onion sets

Transplant outdoors (Eastern and Central PA after last frost): – Broccoli and cabbage starts – Lettuce transplants

Plant trees and shrubs: April is the ideal window for planting bare-root fruit trees, shade trees, and berry bushes across all PA zones. The soil is thawed, moist, and warming — perfect for root establishment before summer heat arrives.

Late Spring: May

May is the green light for warm-season crops statewide. After May 15, even Western PA and mountain gardeners can safely transplant frost-sensitive plants.

Transplant outdoors statewide: – Tomatoes – Peppers – Eggplant – Cucumbers – Squash and zucchini – Melons (zones 6b–7a do best)

Direct sow: – Beans (bush and pole) – Sweet corn – Sunflowers – Pumpkins (for fall harvest)

Fruit planting: May is your last good window for planting strawberries, blueberries, and raspberry canes before summer heat stresses new transplants. Blueberries need acidic soil — PA’s naturally acidic woodland soils can be an advantage here, but test your pH first. A simple soil test kit saves you from guessing.

Summer Maintenance and Succession Planting (June–August)

A lot of people think summer is just maintenance mode — water, weed, repeat. But some of my best harvests come from crops I planted in June and July. Succession planting is the move.

June

Most planting is done by June, but you can still: – Succession plant bush beans every 2–3 weeks for continuous harvest – Direct sow a second round of cucumbers for a late-summer crop – Plant herb transplants (basil loves PA’s humid June weather)

Maintenance priorities: – Mulch around all plants to retain moisture and suppress weeds. PA summers bring plenty of rain, but July dry spells are common. A 2–3 inch layer of organic mulch is your best insurance. – Watch for tomato hornworms and squash vine borers — both are active in PA by late June. – Start training tomato plants to stakes or cages early.

July

July is the hottest month in PA and the hardest on your garden. Focus on keeping things alive and planning for fall.

• Water deeply during dry spells — 1 inch per week minimum, more for containers.
• Harvest garlic when the lower leaves start browning (if you planted last fall).
• Start fall crop seeds indoors: broccoli, cauliflower, and cabbage for August transplanting.

August

August is the start of fall gardening season — even though it doesn’t feel like it yet.

Direct sow for fall harvest: – Lettuce, spinach, arugula – Radishes – Turnips – Kale (one of the best fall crops for PA — it actually tastes better after a light frost) – Beets

Plant for next year: – Order garlic bulbs now for October planting. – Overseed bare spots in your lawn. Late August through mid-September is the best window for grass seed in PA — the soil is warm but the air is cooling down, which is exactly what cool-season grasses like tall fescue and Kentucky bluegrass need.

A broadcast spreader makes overseeding way less tedious, especially if you’re covering more than a small patch.

Fall Planting and Garden Closeout (September–November)

Fall is honestly my favorite time to garden in PA. The heat backs off, the rain comes more reliably, and the soil is still warm enough for roots to establish. It’s one of the best times to plant trees, shrubs, and perennials — and your last shot to get certain crops in the ground.

September

Plant now: – Garlic cloves (plant 4–6 weeks before the ground freezes, typically mid-October to early November in PA) – Spring-flowering bulbs: tulips, daffodils, crocuses, alliums – Trees and shrubs: September through mid-October is an excellent planting window. Trees planted in fall have all winter to establish roots before spring growth. – Cool-season grass seed (first half of September is ideal)

Harvest: – Tomatoes, peppers, and squash before the first frost. – Apples (PA is one of the top apple-producing states — harvest runs September through October depending on variety).

October

Finish planting: – Garlic (if not done in September) – Any remaining spring bulbs – Cover crops like winter rye or crimson clover to protect and enrich bare garden beds over winter

Garden closeout tasks: – Pull spent annual plants and compost them (unless diseased) – Cut back perennials after the first hard frost – Apply a 3–4 inch layer of mulch over perennial beds and around trees for winter insulation

November

By November, the garden is winding down across all of PA.

• Finish mulching perennial beds and tree bases.
• Drain and store hoses before hard freezes.
• Clean, oil, and store garden tools.
• Take notes on what worked and what didn’t — January planning goes much faster when you’ve got notes from the season.

Winter Planning (December–February)

Nothing’s growing outside in a PA winter (unless you’re one of those cold frame people — respect). But honestly, this is when the next season’s success gets decided.

December–January: – Review seed catalogs and order seeds early. Popular varieties sell out by February. – Plan your garden layout. Rotate crops — don’t plant tomatoes where you grew tomatoes last year. – If you’re starting seeds indoors, set up your grow light station by January so it’s ready when seed starting begins in February/March.

February: – Start onion seeds indoors (they need a long head start — 10–12 weeks before transplanting). – Start leeks indoors. – Begin cold-stratifying any perennial or native wildflower seeds that require it. – In zone 7a (Philadelphia area), you can start peas and spinach in cold frames by late February.

Pennsylvania Soil: The Clay Factor

If you garden in PA, you garden in clay. That’s just the deal. According to Penn State Extension’s soil guide, most of the state sits on clay-heavy soils that hold water too long in spring and bake hard in summer. The upside? Clay is mineral-rich, which means it holds nutrients way better than sandy soil.

The trick isn’t fighting the clay — it’s improving it over time:

• Add organic matter every year. Compost, aged manure, leaf mold. Work it into the top 6–8 inches of soil. This is the single most effective thing you can do.
• Don’t work wet clay. If you can squeeze a handful of soil and it forms a sticky ball, wait. Working wet clay destroys its structure and makes drainage worse.
• Raised beds bypass the problem. If your native soil is brutal, a raised bed with quality garden mix gives you instant good soil. This is especially worth it for vegetables and strawberries.
• Gypsum helps in some cases for breaking up compacted clay, but it’s not a silver bullet. It works best on sodic clay, which isn’t the most common type in PA. A soil test will tell you if it’s worth the effort.

Planting Quick-Reference by Crop Type

Vegetables

Fruit

Trees and Shrubs

FAQ