When to Plant Pyrethrum in Ridgefield, WA

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when it's the best time to plant pyrethrum is to examine the USDA zone info for Ridgefield.


Planting Calendar for Pyrethrum

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

You can plant pyrethrum a little bit earlier in the year because they do well in moderate cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant pyrethrum
Possibly ok, but a risky time to plant pyrethrum
Probably not a good time to plant pyrethrum

The earliest that you can plant pyrethrum in Ridgefield 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 really do well. If you are starting your pyrethrum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Ridgefield is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Ridgefield you get a frost after March 15 be ready to cover your pyrethrum in the event of a surprise late frost.

USDA Zone Info for Ridgefield

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 Low15°F
Highest Expected Low20°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 Ridgefield

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