One of the best tools that you have as gardeners to help us estimate 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.

A way of determining when you can plant penstemon is to check out the USDA zone info for Marion.

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 just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant penstemon in Marion 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. You can get started a few weeks earlier by starting your penstemon indoors.

Last Frost Date

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

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Marion and it changes from year to year. Half of the time in Marion you get surprised by a frost after April 15 so make sure that you are prepared to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Marion

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 Marion

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