The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when it's a good idea to plant pyrethrum is to use the USDA zone info for National City.

Planting Calendar for Pyrethrum

Frost tolerance for pyrethrum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Pyrethrum can survive in a little bit of cold which means that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pyrethrum in National City is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant pyrethrum and expect a good harvest is probably October. If you wait any later than that and your pyrethrum may not have a chance to really do well. Starting your pyrethrum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In National City the average date of last frost happens on January 31. It might get as low as 35°F during the coldest months of winter.

Always keep in mind 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 changes 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 prepared to cover your pyrethrum in the event of a surprise 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.