One of the first steps you take when you are figuring out your gardening schedule is find your 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.

One way of making a decision about when it's possible to plant platycodon is to check out the USDA zone info for Caribou.

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 do well in mild cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant platycodon in Caribou 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 fully mature. You can get started a couple of weeks earlier by starting your platycodon indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Caribou. 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 just an average because it is based on the USDA zone info for Caribou and it can change quite a bit from year to year. Half of the time in Caribou there is a last frost after May 15 so always be ready to cover your platycodon in the event of a late frost.

USDA Zone Info for Caribou

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 Caribou

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