When to Plant Penstemon in Mill Creek, WA

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.

It's a good idea to figure out when it's a good idea to plant penstemon by reviewing the USDA zone info for Mill Creek.


Planting Calendar for Penstemon

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

Penstemon are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant penstemon
Possibly ok, but a risky time to plant penstemon
Probably not a good time to plant penstemon

The earliest that you can plant penstemon in Mill Creek 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. If you wait any later than that and your penstemon may not have a chance to grow to maturity. Starting your penstemon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Mill Creek the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Mill Creek is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Mill Creek it frosts late in the year after March 15 be ready to protect your penstemon if you have a late frost.

USDA Zone Info for Mill Creek

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 Low15°F
Highest Expected Low20°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 Mill Creek

You may be interested in your other planting guides for Mill Creek.