The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for New Castle you should be able to determine when it's a good idea to plant penstemon.

Planting Calendar for Penstemon

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

Penstemon do well in moderate cold which means that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant penstemon in New Castle 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 penstemon and expect a good harvest is probably September. Any later than that and your penstemon may not have a chance to really do well. If you are starting your penstemon indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for New Castle may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in New Castle it frosts late in the year after April 15 be ready to cover your penstemon if you have a late frost.

USDA Zone Info for New Castle

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in New Castle

You may be interested in your other planting guides for New Castle.