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

The USDA zone info for Dover should be looked at to determine when it's the best time to plant onions.

Planting Calendar for Onions

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

Onions are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them much earlier than more sensitive plants.

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 little bit earlier by starting your onions indoors.

Last Frost Date

The average date of last frost is April 15 in Dover. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Dover may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Dover it frosts late in the year after April 15 so make sure that you are ready to protect your onions if you have one of those late frosts.

USDA Zone Info for Dover

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°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.