When to Plant Begonias in Riverside, CA

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

A way of making a decision about when it's a good idea to plant begonias is to examine the USDA zone info for Riverside.


Planting Calendar for Begonias

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

You can not plant begonias until after the last frost because they do not do well in cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant begonias
Possibly ok, but a risky time to plant begonias
Probably not a good time to plant begonias

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

Last Frost Date

In Riverside the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind 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. Since half of the time in Riverside there is a last frost after February 15 be ready to cover your begonias in the event of a late frost.

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 Low25°F
Highest Expected Low30°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.