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.

In Riverside you can figure out when it's the best time to plant mimulus by looking at the USDA zone info.

Planting Calendar for Mimulus

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

Since mimulus do not do well in cold weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant mimulus 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 mimulus and expect a good harvest is probably September. If you wait any later than that and your mimulus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your mimulus 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.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Riverside and it changes from year to year. Since half of the time in Riverside you get surprised by a frost after February 15 be ready to cover your mimulus 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 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.