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 it's a good idea to plant platycodon is to refer to the USDA zone info for Merrill.

Planting Calendar for Platycodon

Frost tolerance for platycodon:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Platycodon are barely cold tolerant which means that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant platycodon in Merrill is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant platycodon and expect a good harvest is probably August. If you wait any later than that and your platycodon may not have a chance to grow to maturity. If you are starting your platycodon indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Merrill the average date of last frost happens on May 15. You can expect an average low temperature of -30°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Merrill and it is different every year. Half of the time in Merrill you get a frost after May 15 so always be ready to cover your platycodon if you have a surprise late frost.

USDA Zone Info for Merrill

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Merrill

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