Before planting it is a good idea to find your USDA Zone info to determine 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.

The earliest that you can plant penstemon in Maple Valley can be figured out by looking at 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 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 Maple Valley 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 fully mature. You can get started a couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Maple Valley. It might get as low as 15°F during the coldest months of winter.

Keep in mind that USDA zone info for Maple Valley is just an average and the actual date of last frost changes from year to year. Half of the time in Maple Valley you get surprised by a frost after March 15 so make sure that you are ready to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Maple Valley

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 Maple Valley

You may be interested in your other planting guides for Maple Valley.