One of the best tools that you have as gardeners to help us figure out 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 first opportunity to plant onions in Dover should be estimated by reviewing the USDA zone info.

Planting Calendar for Onions

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

Since onions do well in cold you can plant them earlier in the year than other plants that might not handle the cold.

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

Last Frost Date

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

Keep in mind that USDA zone info for Dover 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 Dover you get a frost after April 15 be ready to protect your onions in the event of one of those late frosts.

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.