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.

In Napa you can determine when to plant sweet potatos by reviewing the USDA zone info.

Planting Calendar for Sweet Potatos

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

Since sweet potatos require warm weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sweet potatos 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 sweet potatos and expect a good harvest is probably September. Any later than that and your sweet potatos may not have a chance to really do well. You can get started a couple of weeks earlier by starting your sweet potatos indoors.

Last Frost Date

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

Remember that USDA zone info for Napa may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Napa you get a frost after February 15 so be sure to be ready to protect your sweet potatos 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.