One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Watertown it's possible to figure out 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 are moderately cold tolerant which means that you can get them planted earlier than other frost tender plants.

The earliest that you can plant oenothera in Watertown is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant oenothera and expect a good harvest is probably August. 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 few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Watertown. You should expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Watertown is not always accurate the actual date of last frost changes from year to year. Half of the time in Watertown it frosts late in the year after May 15 so make sure that you are ready to protect your oenothera if you have one of those late frosts.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°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 -25°F.

Plants to Grow in Watertown

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