Potato shoots and vines do not tolerate frost well, especially a hard frost. Nor do potatoes grow well in wet, soggy soils. At the same time, it’s important to plant early enough to allow the crop to reach maturity. Although potatoes can tolerate a certain amount of insect damage, the Colorado potato beetle can devastate a crop. All of these issues affect planting times.
Potato Varieties for Pennsylvania
As with any vegetable, certain varieties will do better in Pennsylvania growing conditions. Check with other gardeners or a local extension agent. Recommended varieties include:
- Austrian Crescent
- Dark Red Norland
- Michigan Purple
- Purple Majesty
- Yukon Gold.
The USDA Zone in which you garden has a big impact on potato planting times. USDA Zones in Pennsylvania range from Zone 5 to Zone 7. However, there are other factors that may come into play. For example, northwestern counties such as Erie, Warren and Crawford are close enough to Lake Erie that their weather can be affected, making them colder or wetter than southeast counties like Bucks and Chester.
The projected maturity date of a potato variety may have an impact on when you plant potatoes in Pennsylvania. Potatoes may be early, mid-season or late varieties, with expected maturity dates ranging from 75 to 130 days. If you plant one or more varieties in each category, you can plant them all at the same time and harvest potatoes for three months or more as they mature.
Beating the Potato Beetle
The Colorado potato beetle is found in Pennsylvania and can devastate a crop. Beetles produce at least two and sometimes three generations in the state. Timing your plantings can help avoid damage. Your best option is to sprout, or chit, early varieties at least three or four weeks before your last expected frost date. This, plus the short maturity of early varieties means you may have your crop harvested before beetles become a major problem.
Planting by Last Frost Date
Because potato vines are frost sensitive, you don’t want to plant too early. Expected last frost dates range from April 1st to 15th for Zone 5 to March 1st to 15th for Zone 7. If the weather is normal, you could plant unsprouted potatoes two weeks prior to the last projected frost date. In very cold, wet springs, it’s usually better to plant sprouted potatoes on or just after the projected last frost date.