One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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 should be reviewed to determine when it's the best time to plant portulaca.

Planting Calendar for Portulaca

Frost tolerance for portulaca:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since portulaca require warm weather you have to wait until after the last frost when the weather gets warmer before you can plant them.

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

The last month that you can plant portulaca and expect a good harvest is probably August. You probably don't want to wait any later than that or else your portulaca may not have a chance to really do well. You can get started a little bit earlier by starting your portulaca indoors.

Last Frost Date

On average the last frost is on April 15 in Harrisburg. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Harrisburg is just an average the actual date of last frost is different every year. Since half of the time in Harrisburg last frost occurs after April 15 be ready to cover your portulaca in the event of a late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Harrisburg

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