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.

A common way of determining when to plant heliotrope is to examine the USDA zone info for Harrisburg.

Planting Calendar for Heliotrope

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

Heliotrope do not do well in cold weather which tells us that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant heliotrope 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 heliotrope and expect a good harvest is probably August. Any later than that and your heliotrope may not have a chance to grow to maturity. Starting your heliotrope indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Harrisburg. You can expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Harrisburg is not always accurate the actual date of last frost changes from year to year. Since half of the time in Harrisburg you get a frost after April 15 be ready to cover your heliotrope in the event of a surprise 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.