One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when to plant doronicum by referring to the USDA zone info for Petersburg.

Planting Calendar for Doronicum

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

Doronicum do ok in moderate cold which means that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant doronicum in Petersburg 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 doronicum and expect a good harvest is probably September. If you wait any later than that and your doronicum may not have a chance to fully mature. You can get started a little bit earlier by starting your doronicum indoors.

Last Frost Date

The average date of last frost is April 15 in Petersburg. It might get as low as 5°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Petersburg may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Petersburg you get a frost after April 15 be ready to cover your doronicum if you have a late frost.

USDA Zone Info for Petersburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Petersburg

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