One of the first steps you take when you are getting a good idea 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.

The earliest that you can plant twinspur in Harrisburg should be estimated by reviewing the USDA zone info.

Planting Calendar for Twinspur

Frost tolerance for twinspur:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Twinspur do well in moderate cold which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant twinspur 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 twinspur and expect a good harvest is probably September. If you wait any later than that and your twinspur may not have a chance to really do well. You can get started a couple of weeks earlier by starting your twinspur indoors.

Last Frost Date

On average the last frost is on April 15 in Harrisburg. You should expect an average low temperature of 5°F in 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. Half of the time in Harrisburg you get surprised by a frost after April 15 so be sure to be ready to protect your twinspur in the event of 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.