One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant argyranthemum in Napa can be estimated by looking at the USDA zone info.

Planting Calendar for Argyranthemum

Frost tolerance for argyranthemum:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably a bad idea to plant argyranthemum until after the last frost because they require warm weather.

The earliest that you can plant argyranthemum in Napa is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant argyranthemum and expect a good harvest is probably September. If you wait any later than that and your argyranthemum may not have a chance to fully mature. Starting your argyranthemum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Napa. It might get as low as 25°F during the coldest months of winter.

It's important to remember that USDA zone info for Napa is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Napa you get a frost after February 15 so be sure to be ready to cover your argyranthemum if you have a late frost.

USDA Zone Info for Napa

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 Napa

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