Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for San Bernardino you should be able to determine when it's a good idea to plant argyranthemum.

Planting Calendar for Argyranthemum

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

You should not plant argyranthemum until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant argyranthemum in San Bernardino is March. However, you really should wait until April 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. Any later than that and your argyranthemum may not have a chance to grow to maturity. Starting your argyranthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in San Bernardino. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for San Bernardino is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in San Bernardino you get surprised by a frost after February 15 so just be sure to be ready to cover your argyranthemum if you have one of those late frosts.

USDA Zone Info for San Bernardino

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Bernardino

You may be interested in your other planting guides for San Bernardino.