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

In Dover you can figure out when it's the best time to plant penstemon by reviewing 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.

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

The earliest that you can plant penstemon in Dover 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 fully mature. Starting your penstemon indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Dover the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Dover is not always accurate the actual date of last frost is different every year. Half of the time in Dover you get surprised by a frost after April 15 so be sure to be ready to cover your penstemon if you have one of those late frosts.

USDA Zone Info for Dover

Here is the info for USDA Zone 7a.

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

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Dover

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