One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

The USDA zone info for Napa can be looked at to figure out when it's possible to plant euphorbia.

Planting Calendar for Euphorbia

Frost tolerance for euphorbia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since euphorbia are barely cold tolerant you can plant them slightly earlier in the year than other plants that might not handle the cold.

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

The last month that you can plant euphorbia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your euphorbia may not have a chance to grow to maturity. Starting your euphorbia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Napa. You can expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that USDA zone info for Napa is just an average and the actual date of last frost changes from year to year. Since half of the time in Napa you get a frost after February 15 be ready to protect your euphorbia in the event of one of those late frosts.

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.