One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Redwood City you should be able to determine when it's possible to plant pearl onions.

Planting Calendar for Pearl onions

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

Since pearl onions do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant pearl onions in Redwood City 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 pearl onions and expect a good harvest is probably September. If you wait any later than that and your pearl onions may not have a chance to really do well. You can get started a little bit earlier by starting your pearl onions indoors.

Last Frost Date

In Redwood City the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Remember that USDA zone info for Redwood City may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Redwood City it frosts late in the year after February 15 be ready to protect your pearl onions if you have a late frost.

USDA Zone Info for Redwood City

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 Redwood City

You may be interested in your other planting guides for Redwood City.