The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Happy Valley you should be able to estimate when it's a good idea 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.

Since oenothera are moderately cold tolerant you can plant them just a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant oenothera in Happy Valley 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. If you wait any later than that and 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 March 15 in Happy Valley. In the coldest months of winter you can expect an average low temperature of 15°F.

It's important to remember that USDA zone info for Happy Valley is an average and the actual date of last frost will vary from year to year. Half of the time in Happy Valley it frosts late in the year after March 15 so make sure that you are prepared to cover your oenothera if you have a surprise late frost.

USDA Zone Info for Happy Valley

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Happy Valley

You may be interested in your other planting guides for Happy Valley.