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.

In Ripon you can determine when it's possible to plant achillea by using the USDA zone info.

Planting Calendar for Achillea

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

Achillea are very cold tolerant which tells us that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant achillea in Ripon 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 achillea and expect a good harvest is probably October. If you wait any later than that and your achillea may not have a chance to grow to maturity. Starting your achillea indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Ripon. It might get as low as 25°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Ripon and it is different every year. Half of the time in Ripon you get surprised by a frost after February 15 so make sure that you are prepared to protect your achillea if you have a late frost.

USDA Zone Info for Ripon

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 Ripon

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