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.

The USDA zone info for San Mateo can be used to figure out when to plant celosia.

Planting Calendar for Celosia

Frost tolerance for celosia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since celosia require warm weather it is necessary to wait until after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

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

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for San Mateo and it can change quite a bit from year to year. Since half of the time in San Mateo you get surprised by a frost after January 31 be ready to protect your celosia in the event of a late frost.

USDA Zone Info for San Mateo

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 Mateo

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