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.

One way of getting a good idea when to plant browallia is to examine the USDA zone info for Grass Valley.

Planting Calendar for Browallia

Frost tolerance for browallia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since browallia require warm weather it's important to wait until after the last frost before you can plant them.

The earliest that you can plant browallia in Grass Valley is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant browallia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your browallia may not have a chance to fully mature. Starting your browallia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Grass Valley. In the coldest months of winter you can expect an average low temperature of 20°F.

Keep in mind that USDA zone info for Grass Valley is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Grass Valley there is a last frost after February 15 so just be sure to be ready to cover your browallia if you have a surprise late frost.

USDA Zone Info for Grass Valley

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Grass Valley

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