Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when to plant gomphrena by referring to the USDA zone info for San Mateo.

Planting Calendar for Gomphrena

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

Gomphrena are one of those plants that can tolerate a tiny bit of cold weather which means that you can plant them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant gomphrena 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 gomphrena and expect a good harvest is probably September. If you wait any later than that and your gomphrena may not have a chance to grow to maturity. Starting your gomphrena indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Remember that USDA zone info for San Mateo is not always accurate and the actual date of last frost changes from year to year. Since half of the time in San Mateo there is a last frost after January 31 be ready to cover your gomphrena 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.