One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In National City you can figure out when it's a good idea to plant salpiglossis by checking out the USDA zone info.

Planting Calendar for Salpiglossis

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

Since salpiglossis do not do well in cold weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant salpiglossis in National City is February. However, you really should wait until March 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. If you are starting your salpiglossis indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in National City. In the coldest months of winter you can expect an average low temperature of 35°F.

Since the USDA zone info for National City is not always accurate the actual date of last frost changes from year to year. Half of the time in National City you get surprised by a frost after January 31 so just be sure to be ready to protect your salpiglossis if you have one of those late frosts.

USDA Zone Info for National City

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in National City

You may be interested in your other planting guides for National City.