Before planting it is a good idea to find your USDA Zone info to figure out 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.

In Irvine you can determine when you can plant yarrow by looking at the USDA zone info.

Planting Calendar for Yarrow

Frost tolerance for yarrow:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Yarrow are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant yarrow in Irvine 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 yarrow and expect a good harvest is probably October. If you wait any later than that and your yarrow may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your yarrow indoors.

Last Frost Date

On average the last frost is on January 31 in Irvine. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Irvine is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Irvine there is a last frost after January 31 be ready to protect your yarrow in the event of a late frost.

USDA Zone Info for Irvine

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Irvine

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