One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when it's possible to plant penstemon by referring to the USDA zone info for Hartland.

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 do well in moderate cold.

The earliest that you can plant penstemon in Hartland 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. You can get started a little bit earlier by starting your penstemon indoors.

Last Frost Date

In Hartland the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Hartland is just an average the actual date of last frost will vary from year to year. Since half of the time in Hartland you get a frost after April 15 be ready to cover your penstemon in the event of one of those late frosts.

USDA Zone Info for Hartland

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Hartland

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