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 Oswego you can estimate when it's a good idea to plant primroses by reviewing the USDA zone info.

Planting Calendar for Primroses

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

Since primroses are very cold tolerant you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant primroses in Oswego 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 primroses and expect a good harvest is probably September. You probably don't want to wait any later than that or else your primroses may not have a chance to really do well. Starting your primroses indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Oswego. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Oswego and it is different every year. Since half of the time in Oswego you get surprised by a frost after April 15 be ready to cover your primroses in the event of a surprise late frost.

USDA Zone Info for Oswego

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 Oswego

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