The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Gardena you can estimate when it's a good idea to plant tree onions 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.

Since tree onions do ok in moderate cold you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tree onions in Gardena 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. Starting your tree onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Gardena the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 35°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Gardena and it is different every year. Half of the time in Gardena you get surprised by a frost after January 31 so make sure that you are ready to protect your tree onions in the event of a late frost.

USDA Zone Info for Gardena

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Gardena

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