One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's the best time to plant lisianthus by reviewing the USDA zone info for San Jose.

Planting Calendar for Lisianthus

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

Since lisianthus require warm weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant lisianthus in San Jose 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 lisianthus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your lisianthus may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your lisianthus indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for San Jose is not always accurate and the actual date of last frost is different every year. Half of the time in San Jose you get a frost after February 15 so be sure to be ready to protect your lisianthus in the event of a surprise 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.