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.

A way of estimating when you can plant scallions is to use the USDA zone info for San Ramon.

Planting Calendar for Scallions

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

Since scallions are barely cold tolerant you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant scallions in San Ramon 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 scallions and expect a good harvest is probably September. You probably don't want to wait any later than that or else your scallions may not have a chance to grow to maturity. If you are starting your scallions indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In San Ramon the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for San Ramon is not always accurate the actual date of last frost changes from year to year. Since half of the time in San Ramon it frosts late in the year after February 15 be ready to protect your scallions if you have one of those late frosts.

USDA Zone Info for San Ramon

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Ramon

You may be interested in your other planting guides for San Ramon.