Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Danbury you can figure out when you can plant penstemon by checking out the USDA zone info.

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 tells us that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant penstemon in Danbury 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. You probably don't want to wait any later than that or else 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 few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Danbury. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Danbury is just an average the actual date of last frost changes from year to year. Half of the time in Danbury there is a last frost after April 15 so just be sure to be ready to protect your penstemon in the event of a surprise late frost.

USDA Zone Info for Danbury

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Danbury

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