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

The USDA zone info for Riverside should be reviewed to estimate when it's possible to plant lisianthus.

Planting Calendar for Lisianthus

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

You can not plant lisianthus until after the last frost has passed because they require warm weather.

The earliest that you can plant lisianthus in Riverside 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 little bit earlier by starting your lisianthus indoors.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Riverside and it is different every year. Half of the time in Riverside you get surprised by a frost after February 15 so be sure to be ready to cover your lisianthus in the event of one of those late frosts.

USDA Zone Info for Riverside

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 Riverside

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