One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when to plant erysimum is to use the USDA zone info for Phoenix.

Planting Calendar for Erysimum

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

Erysimum do ok in a little bit of cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant erysimum in Phoenix 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 erysimum and expect a good harvest is probably September. If you wait any later than that and your erysimum may not have a chance to fully mature. 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 March 15 in Phoenix. You should expect an average low temperature of 10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Phoenix may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Phoenix you get a frost after March 15 be ready to protect your erysimum in the event of a late frost.

USDA Zone Info for Phoenix

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Phoenix

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