The USDA Zone info is a great tool for gardeners to help us figure out 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.

You can figure out when to plant purple coneflower in Lake Oswego by looking at the USDA zone info.

Planting Calendar for Purple Coneflower

Frost tolerance for purple coneflower:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Purple Coneflower are barely cold tolerant which tells us that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant purple coneflower in Lake Oswego is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant purple coneflower and expect a good harvest is probably August. You probably don't want to wait any later than that or else your purple coneflower may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your purple coneflower indoors.

Last Frost Date

On average all chance of frost has passed is on March 15 in Lake Oswego. You should expect an average low temperature of 15°F in the coldest months of winter.

It's important to remember that USDA zone info for Lake Oswego is an average and the actual date of last frost changes from year to year. Since half of the time in Lake Oswego you get a frost after March 15 be ready to cover your purple coneflower in the event of a surprise late frost.

USDA Zone Info for Lake Oswego

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 Lake Oswego

You may be interested in your other planting guides for Lake Oswego.