One of the first steps you take when you are figuring out 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 best time to plant gomphrena in Portola Valley should be estimated by reviewing the USDA zone info.

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 do well in very little cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant gomphrena in Portola Valley 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. You probably don't want to wait any later than that or else your gomphrena may not have a chance to grow to maturity. If you are starting your gomphrena indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Portola Valley the average date of last frost happens on January 31. In the coldest months of winter you can expect an average low temperature of 30°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Portola Valley and it changes from year to year. Half of the time in Portola Valley you get surprised by a frost after January 31 so just be sure to be ready to cover your gomphrena if you have one of those late frosts.

USDA Zone Info for Portola Valley

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 Portola Valley

You may be interested in your other planting guides for Portola Valley.