One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

The USDA zone info for San Marino can be reffered to in order to figure out when you can plant bidens.

Planting Calendar for Bidens

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

Bidens are not cold tolerant which means that it's necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant bidens in San Marino 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. If you wait any later than that and your bidens may not have a chance to really do well. You can get started a couple of weeks earlier by starting your bidens indoors.

Last Frost Date

The average date of last frost is January 31 in San Marino. In the coldest months of winter you should expect an average low temperature of 30°F.

It's important to remember that USDA zone info for San Marino may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in San Marino you get a frost after January 31 be ready to cover your bidens in the event of one of those late frosts.

USDA Zone Info for San Marino

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 San Marino

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