Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Napa it's a good idea to estimate when you can plant gomphrena.

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 barely cold tolerant which tells us that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant gomphrena in Napa 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 fully mature. 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

The average date of last frost is February 15 in Napa. In the coldest months of winter you should expect an average low temperature of 25°F.

Remember that USDA zone info for Napa may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Napa it frosts late in the year after February 15 so make sure that you are prepared to protect your gomphrena if you have a surprise late frost.

USDA Zone Info for Napa

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Napa

You may be interested in your other planting guides for Napa.