Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 figure out when it's a good idea to plant penstemon by looking at the USDA zone info for Stanwood.

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 mild cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Stanwood 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 fully mature. You can get started a couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

In Stanwood the average date of last frost happens on March 15. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Stanwood is just an average the actual date of last frost is different every year. Half of the time in Stanwood you get surprised by a frost after March 15 so make sure that you are ready to protect your penstemon in the event of a surprise late frost.

USDA Zone Info for Stanwood

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Stanwood

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