The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Dover you can figure out when it's a good idea to plant primula by looking at the USDA zone info.

Planting Calendar for Primula

Frost tolerance for primula:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

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

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

Last Frost Date

The average date of last frost is April 15 in Dover. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Dover and it changes from year to year. Since half of the time in Dover you get surprised by a frost after April 15 be ready to cover your primula if you have a surprise late frost.

USDA Zone Info for Dover

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Dover

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