Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Mercer Island it's possible to determine when it's possible to plant foxglove.

Planting Calendar for Foxglove

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

Foxglove are moderately cold tolerant which tells us that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant foxglove in Mercer Island 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 foxglove and expect a good harvest is probably September. Any later than that and your foxglove may not have a chance to really do well. You can get started a little bit earlier by starting your foxglove indoors.

Last Frost Date

The average date of last frost is March 15 in Mercer Island. You should expect an average low temperature of 15°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Mercer Island and it will vary from year to year. Since half of the time in Mercer Island there is a last frost after March 15 be ready to cover your foxglove if you have a surprise late frost.

USDA Zone Info for Mercer Island

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 Mercer Island

You may be interested in your other planting guides for Mercer Island.