The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Rialto it's a good idea to determine when it's possible to plant pennisetum.

Planting Calendar for Pennisetum

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

Since pennisetum are one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant pennisetum 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 pennisetum and expect a good harvest is probably September. Any later than that and your pennisetum may not have a chance to grow to maturity. You can get started a little bit earlier by starting your pennisetum indoors.

Last Frost Date

In Rialto the average date of last frost happens on January 31. You should expect an average low temperature of 30°F in the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rialto and it will vary from year to year. Since half of the time in Rialto last frost occurs after January 31 be ready to protect your pennisetum if you have 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.