The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when you can plant primroses by checking out the USDA zone info for Riverdale.

Planting Calendar for Primroses

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

Primroses tend to make it in cold weather which tells us that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant primroses in Riverdale 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. Any later than that and your primroses may not have a chance to fully mature. You can get started a few weeks earlier by starting your primroses indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Riverdale. In the coldest months of winter you should expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Riverdale may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Riverdale you get surprised by a frost after April 15 be ready to cover your primroses in the event of one of those late frosts.

USDA Zone Info for Riverdale

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverdale

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