Pennsylvania gardeners must contend with cold winters, mild summers and soil that ranges from clay to sandy. Pennsylvania has 12 distinct soil regions that include sandy beachfront soil near lake Erie and clay-loam soils of the Piedmont region. Gardeners who wish to grow crops in northern Pennsylvania have a very short warm season, and typically select cool-season crops such as lettuce and broccoli over warm-season crops such as tomatoes. Gardeners in southern Pennsylvania have a warmer climate and may choose to grow more warm-season crops.
Test your soil for the soil structure and pH. The Penn State College of Agriculture has a soil testing kit available for $9. The kit is available from the county offices of the Penn State Cooperative Extension service. The test results recommend soil amendments that you can add to your soil to improve it, as well as amounts for each amendment and a schedule for amending your soil.
Determine the last and first frost dates for your area. Seeds should be planted in the ground two weeks before the last frost date, while warm-season bedding plants may be set in the ground anytime after this date. Most warm-season plants will die after the first frost in fall. The last frost of the year occurs in Pennsylvania sometime in April, while the first frost of the year falls in the month of October.
Consult the USDA Plant Hardiness Zone map to determine your hardiness zone. Select plant varieties that are hearty to your zone. Parts of Pennsylvania fall between USDA hardiness zones 4 through 7. Plants such as cold-season vegetables that are hearty to these zones may live through the winter. Plants that are not hardy to your zone, such as warm-season vegetables, should be treated as annuals that will die after the first frost of the season. If you have a short growing season, you should time your spring garden for growing warm-season plants, and grow cool-season plants in your fall garden.
Break up your soil with a rototiller to a depth of 8 inches as soon as the ground is warm enough to be worked. Spread amendments over your soil based on the recommendations made in step 1. Typical soil amendments include peat moss, manure, compost and lime to increase soil pH. Spread these amendments over your soil to a depth of 4 inches. Mix your amendments into the soil by passing a rototiller over the soil again.
Create furrows with a garden hoe in the ground in which to plant your seeds that are twice as deep as the width of the seed. Plant the seeds in the soil and cover them. Dig planting holes in the ground that are twice as wide as the root ball of the plant. Place the root ball in the soil and cover it with dirt.
Check plants daily and water as needed. The soil should remain as damp as a wrung-out sponge.