Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Pomona can be looked at to estimate when it's possible to plant erysimum.

Planting Calendar for Erysimum

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

Erysimum tend to make it in mild cold which means that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant erysimum in Pomona 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. If you wait any later than that and your erysimum may not have a chance to really do well. You can get started a little bit earlier by starting your erysimum indoors.

Last Frost Date

On average the last frost is on January 31 in Pomona. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for Pomona is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Pomona there is a last frost after January 31 be ready to protect your erysimum if you have one of those late frosts.

USDA Zone Info for Pomona

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Pomona

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