One of the best tools that you have as gardeners to help us estimate 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.

The best time to plant gladiolus in South San Francisco should be determined by referring to the USDA zone info.

Planting Calendar for Gladiolus

Frost tolerance for gladiolus:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Gladiolus do well in mild cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant gladiolus 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 gladiolus and expect a good harvest is probably September. If you wait any later than that and your gladiolus may not have a chance to grow to maturity. If you are starting your gladiolus indoors then you might be able to get away with starting them a few weeks earlier.

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 just an average the actual date of last frost will vary from year to year. Since half of the time in South San Francisco you get surprised by a frost after January 31 be ready to cover your gladiolus 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.