The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Palo Alto it's possible to estimate when it's a good idea to plant browallia.

Planting Calendar for Browallia

Frost tolerance for browallia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since browallia are not cold tolerant you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant browallia in Palo Alto 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. If you wait any later than that and 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 Palo Alto. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Palo Alto may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Palo Alto there is a last frost after February 15 be ready to protect your browallia if you have a late frost.

USDA Zone Info for Palo Alto

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 Palo Alto

You may be interested in your other planting guides for Palo Alto.