One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of making a decision about when you can plant oenothera is to examine the USDA zone info for Rialto.

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 earlier in the year because they are moderately cold tolerant.

The earliest that you can plant oenothera in Rialto 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 grow to maturity. You can get started a little bit earlier by starting your oenothera indoors.

Last Frost Date

The average date of last frost is January 31 in Rialto. In the coldest months of winter you can expect an average low temperature of 30°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Rialto and it can change quite a bit from year to year. Since half of the time in Rialto you get surprised by a frost after January 31 be ready to cover your oenothera if you have a surprise late frost.

USDA Zone Info for Rialto

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 Rialto

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