The USDA Zone info is a great tool for gardeners to help us estimate 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.

One way of determining when it's the best time to plant penstemon is to examine the USDA zone info for Sparta.

Planting Calendar for Penstemon

Frost tolerance for penstemon:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since penstemon are moderately cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant penstemon in Sparta 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. You probably don't want to wait any later than that or else your penstemon may not have a chance to grow to maturity. Starting your penstemon indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Sparta. You can expect an average low temperature of -25°F in the coldest months of winter.

Remember that USDA zone info for Sparta is just an average and the actual date of last frost is different every year. Since half of the time in Sparta you get surprised by a frost after May 15 be ready to cover your penstemon in the event of a late frost.

USDA Zone Info for Sparta

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 Sparta

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