One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's the best time to plant penstemon by referring to the USDA zone info for Ithaca.

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 earlier than other frost tender plants.

The earliest that you can plant penstemon in Ithaca 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. If you wait any later than that and your penstemon may not have a chance to really do well. Starting your penstemon indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ithaca. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for Ithaca is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Ithaca you get surprised by a frost after April 15 be ready to cover your penstemon in the event of a late frost.

USDA Zone Info for Ithaca

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 Ithaca

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