Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when it's a good idea to plant primroses by referring to the USDA zone info for Watertown.

Planting Calendar for Primroses

Frost tolerance for primroses:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant primroses much earlier in the year because they are very cold tolerant.

The earliest that you can plant primroses 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 primroses and expect a good harvest is probably August. Any later than that and your primroses may not have a chance to fully mature. You can get started a little bit earlier by starting your primroses indoors.

Last Frost Date

The average date of last frost is May 15 in Watertown. In the coldest months of winter you can expect an average low temperature of -25°F.

Remember that USDA zone info for Watertown may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Watertown you get a frost after May 15 so make sure that you are prepared to cover your primroses in the event of a late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Watertown

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