One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant bidens in National City can be determined by using the USDA zone info.

Planting Calendar for Bidens

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

Bidens do not do well in cold weather which means that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant bidens 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 bidens and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bidens may not have a chance to fully mature. If you are starting your bidens indoors then you might be able to get away with starting them a little bit earlier.

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 just an average because it is based on the USDA zone info for National City and it can change quite a bit from year to year. Half of the time in National City there is a last frost after January 31 so make sure that you are ready to protect your bidens 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.