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.

You can figure out when it's possible to plant primula in Winona by referring to the USDA zone info.

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 pretty solid cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant primula in Winona 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. You probably don't want to wait any later than that or else your primula may not have a chance to fully mature. If you are starting your primula indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Winona may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Winona last frost occurs after May 15 so always be ready to cover your primula if you have a surprise late frost.

USDA Zone Info for Winona

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 Winona

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