The USDA Zone info is a great tool for gardeners to help us determine 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.

A common way of making a decision about when to plant tree onions is to use the USDA zone info for Redlands.

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 tend to make it in mild cold which means that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tree onions in Redlands 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. You probably don't want to wait any later than that or else your tree onions may not have a chance to fully mature. If you are starting your tree onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Redlands and it can change quite a bit from year to year. Since half of the time in Redlands it frosts late in the year after February 15 be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Redlands

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 Redlands

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