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

One way of estimating when it's the best time to plant hosta is to use the USDA zone info for Rialto.

Planting Calendar for Hosta

Frost tolerance for hosta:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Hosta can survive in mild cold which means that you can plant them a little bit earlier in the year than other frost tender plants.

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

The last month that you can plant hosta and expect a good harvest is probably October. Any later than that and your hosta may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hosta indoors.

Last Frost Date

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

Remember 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 it frosts late in the year after January 31 be ready to cover your hosta 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.