One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Chehalis you should be able to estimate when it's possible to plant pyrethrum.

Planting Calendar for Pyrethrum

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

Pyrethrum tend to make it in moderate cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pyrethrum in Chehalis 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. If you wait any later than that and your pyrethrum may not have a chance to fully mature. Starting your pyrethrum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Chehalis. In the coldest months of winter you should expect an average low temperature of 10°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Chehalis and it is different every year. Half of the time in Chehalis it frosts late in the year after March 15 so make sure that you are ready to cover your pyrethrum if you have a surprise late frost.

USDA Zone Info for Chehalis

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Chehalis

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