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 estimate when it's a good idea to plant rosemary by using the USDA zone info for Harrisburg.

Planting Calendar for Rosemary

Frost tolerance for rosemary:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since rosemary do well in cold you can plant them quite a bit earlier in the year than more sensitive plants.

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

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

Last Frost Date

In Harrisburg the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Harrisburg may not be accurate from year to year the actual date of last frost will vary 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 rosemary in the event of a late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7a.

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

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Harrisburg

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