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.

A way of figuring out when it's the best time to plant impatiens is to use the USDA zone info for National City.

Planting Calendar for Impatiens

Frost tolerance for impatiens:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Impatiens do not do well in cold weather which means that it's necessary 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 impatiens 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 impatiens and expect a good harvest is probably September. Any later than that and your impatiens may not have a chance to really do well. If you are starting your impatiens indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In National City the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 35°F.

Since the USDA zone info for National City is an average the actual date of last frost will vary from year to year. Half of the time in National City it frosts late in the year after January 31 so be sure to be ready to protect your impatiens in the event of 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.