The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Napa it's possible to determine when it's possible to plant tomatos.

Planting Calendar for Tomatos

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

You really shouldn't plant tomatos until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant tomatos 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 tomatos and expect a good harvest is probably September. If you wait any later than that and your tomatos may not have a chance to fully mature. Starting your tomatos indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Napa is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Napa it frosts late in the year after February 15 so make sure that you are prepared to cover your tomatos 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.