The USDA Zone info is a great tool for gardeners to help us determine 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.

One way of getting a good idea when you can plant platycodon is to look at the USDA zone info for Duluth.

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.

Since platycodon do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant platycodon in Duluth 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. Any later than that and your platycodon may not have a chance to grow to maturity. Starting your platycodon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Duluth. It might get as low as -30°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Duluth and it can change quite a bit from year to year. Since half of the time in Duluth you get surprised by a frost after May 15 be ready to cover your platycodon in the event of one of those late frosts.

USDA Zone Info for Duluth

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 Duluth

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