One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for South San Francisco can be read to figure out when to plant iresene.

Planting Calendar for Iresene

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

Iresene require warm weather which means that you have to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant iresene in South San Francisco 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 iresene and expect a good harvest is probably September. Any later than that and your iresene may not have a chance to really do well. You can get started a couple of weeks earlier by starting your iresene indoors.

Last Frost Date

The average date of last frost is January 31 in South San Francisco. You can expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for South San Francisco is an average the actual date of last frost is different every year. Since half of the time in South San Francisco there is a last frost after January 31 be ready to cover your iresene in the event of one of those late frosts.

USDA Zone Info for South San Francisco

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 South San Francisco

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