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

A way of determining when to plant erysimum is to consult the USDA zone info for Zone 9b.

Planting Calendar for Erysimum

Frost tolerance for erysimum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Erysimum do well in moderate cold which means that you can start planting them earlier than more sensitive plants.

The earliest that you can plant erysimum in Zone 9b 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 erysimum and expect a good harvest is probably October. You probably don't want to wait any later than that or else your erysimum may not have a chance to really do well. If you are starting your erysimum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Zone 9b. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Zone 9b is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 9b you get surprised by a frost after February 15 so be sure to be ready to cover your erysimum if you have a surprise late frost.

USDA Zone Info for Zone 9b

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 Zone 9b

You may be interested in your other planting guides for Zone 9b.