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

You should be able to estimate when to plant penstemon by checking out the USDA zone info for Norwalk.

Planting Calendar for Penstemon

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

Penstemon do well in moderate cold which tells us that you can plant them a little bit earlier than more sensitive plants.

The earliest that you can plant penstemon in Norwalk 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. 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 April 15 in Norwalk. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Norwalk may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Norwalk it frosts late in the year after April 15 be ready to protect your penstemon if you have one of those late frosts.

USDA Zone Info for Norwalk

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

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

Plants to Grow in Norwalk

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