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.

In Lake Oswego you can determine when you can plant centaurea by looking at the USDA zone info.

Planting Calendar for Centaurea

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

Centaurea do well in a little bit of 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 centaurea in Lake Oswego 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 centaurea and expect a good harvest is probably September. You probably don't want to wait any later than that or else your centaurea may not have a chance to grow to maturity. You can get started a little bit earlier by starting your centaurea indoors.

Last Frost Date

The average date of last frost is March 15 in Lake Oswego. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Lake Oswego is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Lake Oswego you get a frost after March 15 so make sure that you are prepared to protect your centaurea if you have one of those late frosts.

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.