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 first chance to plant pyrethrum in Tualatin should be determined by checking out the USDA zone info.

Planting Calendar for Pyrethrum

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

Pyrethrum are moderately cold tolerant which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant pyrethrum in Tualatin 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 pyrethrum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your pyrethrum may not have a chance to grow to maturity. Starting your pyrethrum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Tualatin the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 15°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Tualatin and it is different every year. Half of the time in Tualatin you get a frost after March 15 so make sure that you are ready to protect your pyrethrum in the event of a late frost.

USDA Zone Info for Tualatin

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 Tualatin

You may be interested in your other planting guides for Tualatin.