One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Harrisburg can be reviewed to determine when it's the best time to plant sweet peas.

Planting Calendar for Sweet Peas

Frost tolerance for sweet peas:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Sweet Peas are barely cold tolerant which means that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant sweet peas in Harrisburg is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant sweet peas and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet peas may not have a chance to really do well. If you are starting your sweet peas indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Harrisburg. You should expect an average low temperature of 5°F in the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Harrisburg and it changes from year to year. Half of the time in Harrisburg last frost occurs after April 15 so make sure that you are ready to protect your sweet peas if you have a late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Harrisburg

You may be interested in your other planting guides for Harrisburg.