Before planting it is a good idea to find your USDA Zone info to determine 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.

One way of figuring out when it's the best time to plant doronicum is to check out the USDA zone info for Zone 1a.

Planting Calendar for Doronicum

Frost tolerance for doronicum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Doronicum are one of those plants that can tolerate a little bit of cold weather which means that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant doronicum in Zone 1a is May. However, you really should wait until June if you don't want to take any chances.

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

Last Frost Date

On average the last frost has passed is on June 15 in Zone 1a. You should expect an average low temperature of -60°F in 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 Zone 1a and it is different every year. Half of the time in Zone 1a you get a frost after June 15 so make sure that you are ready to protect your doronicum in the event of one of those late frosts.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-60°F
Highest Expected Low	-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in your other planting guides for Zone 1a.