The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Napa should be reviewed to determine when it's possible to plant nasturtium.

Planting Calendar for Nasturtium

Frost tolerance for nasturtium:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since nasturtium are not cold tolerant it is important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant nasturtium 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 nasturtium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your nasturtium may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your nasturtium indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Napa and it will vary from year to year. Since half of the time in Napa there is a last frost after February 15 be ready to protect your nasturtium if you have a surprise 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.