When To Plant Garden In Pa

Figuring out when to plant garden in PA can feel like a puzzle with moving pieces. Our state’s diverse climate means timing is everything for a successful harvest.

Pennsylvania stretches across USDA Hardiness Zones 5b to 7a. This means winter lows can range from -15°F to 10°F. Your specific zone is the first clue to your planting schedule.

Spring frost dates are your biggest guide. The last average frost in spring can be as early as late April in southeastern PA and as late as mid-May in the northern tier. A fall frost can arrive as early as September in the mountains.

This guide breaks down the year into seasons. We’ll cover what to plant and when, from the earliest spring seeds to the last fall crops.

Understanding Your Pennsylvania Microclimate

Your exact location creates a microclimate. Urban areas, like Philadelphia, hold heat longer. Valleys can trap cold air, causing frost pockets.

South-facing slopes warm up faster in spring. Lake Erie’s influence moderates temperatures in the northwest. Observe your own garden’s conditions each year.

Use your county’s cooperative extension service for localized frost date charts.
Track your garden’s temperature with a simple thermometer.
Note which areas thaw and dry out first after winter.

Spring Planting Guide (March – May)

Spring is a season of patience. Rushing to plant tender crops too early is a common mistake. We work from hardy to tender plants.

Early Spring (As soon as soil is workable)

This is when the soil is no longer frozen and isn’t a soggy mess. You can perform the “squeeze test”: grab a handful of soil. If it forms a ball that crumbles easily, it’s ready.

Plant peas, spinach, kale, and lettuce seeds directly in the garden.
Transplant onion sets and hardy perennial herbs like thyme.
Plant bare-root trees and shrubs before they break dormancy.

Mid-Spring (2-4 weeks before last frost)

This is prime time for cool-season crops. They can tolerate a light frost and grow best in cooler temperatures.

Direct sow: radishes, carrots, beets, Swiss chard, and turnips.
Transplant: broccoli, cabbage, and cauliflower seedlings you started indoors.
Potatoes can be planted around St. Patrick’s Day, a traditional benchmark.

Late Spring (After last frost date)

Now we wait for the danger of frost to pass. This is when summer’s stars go into the ground. Always harden off indoor-started plants for a week first.

Transplant tomatoes, peppers, eggplants, and basil.
Direct sow beans, corn, cucumber, and squash seeds.
Plant tender annual flowers like marigolds and zinnias.

Summer Planting Guide (June – August)

Summer is for maintenance and succession planting. To keep your harvest coming, you can plant certain crops multiple times.

In early June, you can still plant another round of beans, corn, and summer squash. By mid-July, start thinking about fall. Many gardeners forget that fall gardening is highly productive.

In late July, direct sow carrots, beets, and bush beans for a fall crop.
Start broccoli, cabbage, and Brussels sprouts seeds indoors in mid-June for July transplanting.
Keep harvesting regularly to encourage more production from plants like zucchini.

Fall Planting Guide (September – November)

Fall often provides the best growing conditions—warm soil, cool air, and fewer pests. The goal is to time crops to mature before hard freezes.

Early Fall (6-8 weeks before first frost)

Transplant your seedlings of broccoli and cauliflower. Direct sow quick growers like spinach, lettuce, and radishes. These crops thrive in the shortening days.

Late Fall (Onions, Garlic, and Overwintering)

This is the time for next year’s alliums. Plant garlic cloves and onion sets in October to November. They’ll root before the ground freezes and shoot up early in spring.

You can also plant a cover crop, like winter rye, in empty beds to protect the soil. Some kale and spinach, if protected with a row cover, may even survive winter for early spring greens.

Using Season Extension Techniques

Don’t let the calendar limit you. Simple tools can add weeks to both ends of your growing season.

Cold Frames: Basically a mini-greenhouse. Use them to harden off seedlings or grow cold-hardy greens into winter.
Row Covers: Lightweight fabric laid over crops. It provides a few degrees of frost protection and keeps pests off.
Mulch: A thick layer of straw or leaves insulates soil. It keeps root vegetables from freezing hard and can be pulled back to harvest.

A Simple Month-by-Month Checklist

This list gives you a general timeline. Always adjust for your specific zone and that year’s weather patterns.

March: Prune fruit trees, start seeds indoors (peppers, tomatoes), plant peas late in the month if soil is workable.
April: Direct sow cool-season crops, transplant early seedlings, plant potatoes and onion sets.
May: Transplant tender crops after frost, direct sow corn and beans, keep an eye out for late frost warnings.
June: Succession plant beans/corn, start fall brassica seeds indoors, mulch garden beds.
July: Plant fall carrots and beets, harvest garlic, keep watering consistently during dry spells.
August: Sow lettuce and spinach for fall, transplant fall broccoli, order garlic for fall planting.
September: Plant more greens, harvest winter squash, begin cleaning up spent summer plants.
October: Plant garlic and onion sets, add compost to empty beds, use row covers to extend harvest.

Common Planting Mistakes to Avoid

Even experienced gardeners can make these errors. Being aware of them saves alot of frustration.

Planting too early in cold, wet soil. Seeds will rot, and plants won’t grow.
Not hardening off seedlings. Moving them directly from indoors to the garden shocks them, stunting growth.
Ignoring soil temperature. A soil thermometer is a cheap, invaluable tool. Tomatoes need soil above 60°F, for example.
Crowding plants. Follow spacing on seed packets for good air flow, which prevents disease.

FAQ: Pennsylvania Garden Planting

When is the best time to plant a vegetable garden in Pennsylvania?
The “best time” is staggered. Cool-season crops go in early spring (April) and again in late summer (August). Warm-season crops are planted after the last spring frost, usually from mid-May onward.

What can I plant in April in PA?
In April, you can plant peas, lettuce, spinach, radishes, carrots, beets, kale, potatoes, and onion sets. Transplant broccoli and cabbage seedlings if you started them indoors.

How do I find my exact frost dates?
The best resource is the Penn State Extension website. They have detailed charts by county. Remember, these are averages; always watch the local forcast.

Is it to late to plant a garden in June?
Not at all! You can plant beans, corn, squash, and cucumbers in early June. You can also start seeds for fall crops like broccoli and Brussels sprouts indoors to transplant in July.

What should I plant in fall in Pennsylvania?
Great fall crops include lettuce, spinach, kale, radishes, carrots, beets, and turnips. Also, plant garlic in October for a harvest next summer.

By following these guidelines and observing your own garden’s conditions, you’ll develop a feel for the perfect when to plant garden in PA schedule. Keep a simple journal each year noting what you planted when and how it performed. This personal record becomes your most valuable tool for gardening success in our ever-changing Pennsylvania climate.