Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Milpitas you can determine when it's possible to plant onions by reviewing the USDA zone info.

Planting Calendar for Onions

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

Since onions are very cold tolerant you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant onions in Milpitas 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. If you wait any later than that and your onions may not have a chance to grow to maturity. If you are starting your onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Milpitas. In the coldest months of winter you can expect an average low temperature of 25°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Milpitas and it can change quite a bit from year to year. Since half of the time in Milpitas you get surprised by a frost after February 15 be ready to cover your onions if you have a surprise late frost.

USDA Zone Info for Milpitas

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 Milpitas

You may be interested in your other planting guides for Milpitas.