One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of determining when to plant primroses is to use the USDA zone info for Marshall.

Planting Calendar for Primroses

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

Primroses are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them a quite a bit earlier than other plants that might not handle the cold.

The earliest that you can plant primroses in Marshall 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. You can get started a couple of weeks earlier by starting your primroses indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Marshall. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Marshall is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Marshall 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 Marshall

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 Marshall

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