Before planting it is a good idea to find your USDA Zone info to figure out 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.

It's a good idea to estimate when it's possible to plant violas by using the USDA zone info for San Jose.

Planting Calendar for Violas

Frost tolerance for violas:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Violas do well in cold which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant violas in San Jose is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant violas and expect a good harvest is probably October. You probably don't want to wait any later than that or else your violas may not have a chance to fully mature. If you are starting your violas indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on February 15 in San Jose. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for San Jose is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in San Jose it frosts late in the year after February 15 be ready to protect your violas if you have a late frost.

USDA Zone Info for San Jose

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 San Jose

You may be interested in your other planting guides for San Jose.