One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when to plant trailing portulaca by looking at the USDA zone info for Harrisburg.

Planting Calendar for Trailing Portulaca

Frost tolerance for trailing portulaca:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Trailing Portulaca require warm weather which means that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant trailing 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 trailing portulaca and expect a good harvest is probably August. If you wait any later than that and your trailing portulaca may not have a chance to grow to maturity. You can get started a little bit earlier by starting your trailing portulaca indoors.

Last Frost Date

In Harrisburg the average date of last frost happens on April 15. You can expect an average low temperature of 5°F in the coldest months of winter.

Keep in mind that USDA zone info for Harrisburg is an average and the actual date of last frost changes from year to year. Since half of the time in Harrisburg it frosts late in the year after April 15 be ready to cover your trailing portulaca if you have one of those late frosts.

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.