One of the first steps you take when you are getting a good idea 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.

It's a good idea to figure out when you can plant yarrow by checking out the USDA zone info for Roma.

Planting Calendar for Yarrow

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

Yarrow are very cold tolerant which tells us that you can get them planted much earlier than plants that are more sensitive to the cold.

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

Last Frost Date

In Roma the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Roma is not always accurate the actual date of last frost changes from year to year. Since half of the time in Roma you get a frost after February 15 be ready to cover your yarrow in the event of a surprise late frost.

USDA Zone Info for Roma

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Roma

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