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.

The first opportunity to plant salpiglossis in Napa can be determined by looking at the USDA zone info.

Planting Calendar for Salpiglossis

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

It's probably not a good idea to plant salpiglossis until after the last frost when the weather gets warmer because they are not cold tolerant.

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

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 just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Napa last frost occurs after February 15 be ready to protect your salpiglossis in the event of 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.