Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Stuttgart you can estimate when it's the best time to plant penstemon by using the USDA zone info.

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 one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Stuttgart 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. 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 couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Stuttgart. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Stuttgart may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Stuttgart it frosts late in the year after March 15 so make sure that you are ready to cover your penstemon in the event of one of those late frosts.

USDA Zone Info for Stuttgart

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Stuttgart

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