One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when to plant pentas by reviewing the USDA zone info for Harrisburg.

Planting Calendar for Pentas

Frost tolerance for pentas:	Not tolerant of frost.
When to plant:	After the last frost.

Since pentas do not do well in cold weather it's important to wait until after all chance of frost has passed before you can plant them.

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

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Harrisburg and it can change quite a bit from year to year. Half of the time in Harrisburg there is a last frost after April 15 so always be ready to protect your pentas 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.