Before planting it is a good idea to find your USDA Zone info to estimate 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.

In Berthoud you can figure out when it's possible to plant oenothera by checking out 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.

Oenothera tend to make it in some cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant oenothera in Berthoud 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. Starting your oenothera indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Berthoud the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Berthoud and it is different every year. Half of the time in Berthoud you get a frost after April 15 so make sure that you are prepared to cover your oenothera if you have one of those late frosts.

USDA Zone Info for Berthoud

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Berthoud

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