The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Monticello should be used to estimate when you can plant penstemon.

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 Monticello is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant penstemon and expect a good harvest is probably August. If you wait any later than that and 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 Monticello the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Monticello is just an average the actual date of last frost changes from year to year. Since half of the time in Monticello you get surprised by a frost after May 15 be ready to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Monticello

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Monticello

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