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

By looking at the USDA zone info for Phoenix you should be able to determine when it's the best time to plant oenothera.

Planting Calendar for Oenothera

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

You can plant oenothera a little bit earlier in the year because they do well in moderate cold.

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

Last Frost Date

The average date of last frost is February 15 in Phoenix. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Phoenix is not always accurate the actual date of last frost changes from year to year. Since half of the time in Phoenix last frost occurs after February 15 be ready to protect your oenothera in the event of one of those late frosts.

USDA Zone Info for Phoenix

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 Phoenix

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