The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 figure out when to plant primroses by reviewing the USDA zone info for Dayton.

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 earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant primroses in Dayton 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. You probably don't want to wait any later than that or else your primroses may not have a chance to fully mature. Starting your primroses indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Dayton. It might get as low as -25°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Dayton and it is different every year. Since half of the time in Dayton you get a frost after May 15 be ready to protect your primroses if you have one of those late frosts.

USDA Zone Info for Dayton

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 Dayton

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