Before planting it is a good idea to find your USDA Zone info to estimate 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 Napa you can determine when you can plant basil by looking at the USDA zone info.

Planting Calendar for Basil

Frost tolerance for basil:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant basil until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant basil 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 basil and expect a good harvest is probably September. Any later than that and your basil may not have a chance to fully mature. Starting your basil indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Napa. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Napa is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Napa you get surprised by a frost after February 15 so make sure that you are prepared to protect your basil if you have 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.