The USDA Zone info is a great tool for gardeners to help us estimate 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.

The USDA zone info for Napa can be reviewed to determine when it's a good idea to plant oxalis.

Planting Calendar for Oxalis

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

Oxalis require warm weather which means that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

The average date of last frost is February 15 in Napa. It might get as low as 25°F during the coldest months of winter.

It's important 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 is different every year. Since half of the time in Napa you get surprised by a frost after February 15 be ready to protect your oxalis if you have a 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.