The USDA Zone info is a great tool for gardeners to help us determine 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.

You will be able to estimate when you can plant penstemon by referring to the USDA zone info for Warren.

Planting Calendar for Penstemon

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

You can plant penstemon a little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant penstemon in Warren 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 fully mature. If you are starting your penstemon indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Warren the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that USDA zone info for Warren is just an average and the actual date of last frost will vary from year to year. Half of the time in Warren it frosts late in the year after April 15 so make sure that you are prepared to cover your penstemon if you have a surprise late frost.

USDA Zone Info for Warren

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 Warren

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