The USDA Zone info is a great tool for gardeners to help us estimate 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.

It's possible to estimate when it's possible to plant tarragon by using the USDA zone info for Rialto.

Planting Calendar for Tarragon

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

Tarragon do ok in moderate cold which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant tarragon 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 tarragon and expect a good harvest is probably September. You probably don't want to wait any later than that or else your tarragon may not have a chance to fully mature. Starting your tarragon indoors is a great way to get them started a few weeks earlier.

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.

Just be sure to 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 changes from year to year. Since half of the time in Rialto it frosts late in the year after January 31 be ready to protect your tarragon 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.