One of the best tools that you have as gardeners to help us figure out 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 determine when it's the best time to plant morning glory by looking at the USDA zone info.

Planting Calendar for Morning Glory

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

It's probably a bad idea to plant morning glory until after the last frost has passed because they are not cold tolerant.

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

Last Frost Date

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

Remember that the actual date of last frost is an average because it is based on the USDA zone info for National City and it will vary from year to year. Since half of the time in National City you get surprised by a frost after January 31 be ready to protect your morning glory in the event of a late frost.

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.