Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Philadelphia you can figure out when it's the best time to plant twinspur by referring to 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.

Since twinspur do well in moderate cold you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant twinspur in Philadelphia 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. You probably don't want to wait any later than that or else your twinspur may not have a chance to fully mature. You can get started a little bit earlier by starting your twinspur indoors.

Last Frost Date

In Philadelphia the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Philadelphia and it is different every year. Since half of the time in Philadelphia there is a last frost after March 15 be ready to cover your twinspur in the event of a late frost.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Philadelphia

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