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.

The best time to plant tree onions in Watsonville can be figured out by looking at the USDA zone info.

Planting Calendar for Tree onions

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

Tree onions are barely cold tolerant which tells us that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant tree onions in Watsonville 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 tree onions and expect a good harvest is probably September. If you wait any later than that and your tree onions may not have a chance to really do well. If you are starting your tree onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Watsonville the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Remember that USDA zone info for Watsonville is just an average and the actual date of last frost will vary from year to year. Half of the time in Watsonville you get surprised by a frost after February 15 so just be sure to be ready to protect your tree onions in the event of a late frost.

USDA Zone Info for Watsonville

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 Watsonville

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