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

The earliest that you can plant euphorbia in Rialto should be determined by reviewing the USDA zone info.

Planting Calendar for Euphorbia

Frost tolerance for euphorbia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Euphorbia are barely cold tolerant which tells us that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant euphorbia in Rialto is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant euphorbia and expect a good harvest is probably September. Any later than that and your euphorbia may not have a chance to really do well. You can get started a little bit earlier by starting your euphorbia indoors.

Last Frost Date

On average the last frost is on January 31 in Rialto. In the coldest months of winter you can expect an average low temperature of 30°F.

Remember that USDA zone info for Rialto is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Rialto there is a last frost after January 31 be ready to cover your euphorbia in the event of a late frost.

USDA Zone Info for Rialto

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Rialto

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