Before planting it is a good idea to find your USDA Zone info to figure out 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.

A common way of determining when you can plant primula is to check out the USDA zone info for Chaska.

Planting Calendar for Primula

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

Primula do ok in quite a bit of cold which tells us that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant primula in Chaska 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 primula and expect a good harvest is probably August. Any later than that and your primula may not have a chance to grow to maturity. Starting your primula indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Chaska the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Chaska and it will vary from year to year. Half of the time in Chaska there is a last frost after May 15 so be sure to be ready to protect your primula if you have one of those late frosts.

USDA Zone Info for Chaska

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 Chaska

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