One of the first steps you take when you are determining 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.

In Kennewick you can determine when to plant oenothera by referring to the USDA zone info.

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 bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant oenothera in Kennewick 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 oenothera and expect a good harvest is probably September. Any later than that and your oenothera may not have a chance to really do well. If you are starting your oenothera indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Kennewick. It might get as low as 0°F during the coldest months of winter.

Remember that USDA zone info for Kennewick is just an average and the actual date of last frost is different every year. Since half of the time in Kennewick there is a last frost after April 15 be ready to cover your oenothera in the event of one of those late frosts.

USDA Zone Info for Kennewick

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Kennewick

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