One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of determining when it's possible to plant pyrethrum is to examine the USDA zone info for Ukiah.

Planting Calendar for Pyrethrum

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

Pyrethrum are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant pyrethrum in Ukiah is January. However, you really should wait until February if you don't want to take any chances.

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

Last Frost Date

The average date of last frost is February 15 in Ukiah. In the coldest months of winter you should expect an average low temperature of 20°F.

Since the USDA zone info for Ukiah is just an average the actual date of last frost will vary from year to year. Half of the time in Ukiah you get a frost after February 15 so be sure to be ready to protect your pyrethrum if you have one of those late frosts.

USDA Zone Info for Ukiah

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Ukiah

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