One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Rialto should be read to figure out when you can plant leeks.

Planting Calendar for Leeks

Frost tolerance for leeks:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

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

The earliest that you can plant leeks 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 leeks and expect a good harvest is probably October. You probably don't want to wait any later than that or else your leeks may not have a chance to fully mature. You can get started a little bit earlier by starting your leeks indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Rialto. You should expect an average low temperature of 30°F in the coldest months of winter.

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 can change quite a bit from year to year. Since half of the time in Rialto last frost occurs after January 31 be ready to cover your leeks in the event of one of those late frosts.

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.