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.

You should be able to figure out when it's a good idea to plant argyranthemum by looking at the USDA zone info for Millbrae.

Planting Calendar for Argyranthemum

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

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

The earliest that you can plant argyranthemum in Millbrae 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 argyranthemum and expect a good harvest is probably September. If you wait any later than that and your argyranthemum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your argyranthemum indoors.

Last Frost Date

On average the last frost has passed is on January 31 in Millbrae. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for Millbrae is not always accurate the actual date of last frost changes from year to year. Half of the time in Millbrae last frost occurs after January 31 so always be ready to cover your argyranthemum in the event of a surprise late frost.

USDA Zone Info for Millbrae

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Millbrae

You may be interested in your other planting guides for Millbrae.