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.

By using the USDA zone info for Ballwin it's possible to determine when you can plant primula.

Planting Calendar for Primula

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

Since primula are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant primula in Ballwin 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 primula and expect a good harvest is probably September. Any later than that and your primula may not have a chance to really do well. 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

On average the last frost has passed is on April 15 in Ballwin. You can expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for Ballwin is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Ballwin there is a last frost after April 15 so always be ready to cover your primula in the event of a late frost.

USDA Zone Info for Ballwin

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 Ballwin

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