One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Dover should be used to estimate when it's possible to plant columbine.

Planting Calendar for Columbine

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

Columbine are moderately cold tolerant which means that you can start planting them earlier than plants that are more sensitive to the cold.

The earliest that you can plant columbine in Dover 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 columbine and expect a good harvest is probably September. You probably don't want to wait any later than that or else your columbine may not have a chance to fully mature. You can get started a little bit earlier by starting your columbine indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Dover. In the coldest months of winter you should expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Dover is just an average and the actual date of last frost changes from year to year. Half of the time in Dover it frosts late in the year after April 15 so always be ready to protect your columbine if you have a late frost.

USDA Zone Info for Dover

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Dover

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