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.

One way of determining when it's the best time to plant onions is to check out the USDA zone info for Simi Valley.

Planting Calendar for Onions

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

Onions are very cold tolerant which tells us that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant onions in Simi Valley 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 onions and expect a good harvest is probably October. You probably don't want to wait any later than that or else your onions may not have a chance to fully mature. Starting your onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Simi Valley. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Simi Valley is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Simi Valley last frost occurs after February 15 be ready to cover your onions if you have one of those late frosts.

USDA Zone Info for Simi Valley

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 Simi Valley

You may be interested in your other planting guides for Simi Valley.