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

A common way of making a decision about when it's possible to plant penstemon is to look at the USDA zone info for Mount Vernon.

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 do well in moderate cold.

The earliest that you can plant penstemon in Mount Vernon 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 grow to maturity. 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

On average the last frost is on April 15 in Mount Vernon. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for Mount Vernon may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Mount Vernon it frosts late in the year after April 15 be ready to protect your penstemon if you have a late frost.

USDA Zone Info for Mount Vernon

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 Mount Vernon

You may be interested in your other planting guides for Mount Vernon.