Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Hayden it's a good idea to determine when it's possible 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.

Oenothera tend to make it in some cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant oenothera in Hayden 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. You probably don't want to wait any later than that or else 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 few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Hayden. You should expect an average low temperature of -5°F in the coldest months of winter.

Keep in mind that USDA zone info for Hayden is an average and the actual date of last frost will vary from year to year. Since half of the time in Hayden you get surprised by a frost after April 15 be ready to protect your oenothera if you have a surprise late frost.

USDA Zone Info for Hayden

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Hayden

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