One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Dover you can figure out when you can plant tree onions by checking out the USDA zone info.

Planting Calendar for Tree onions

Frost tolerance for tree onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since tree onions are barely cold tolerant you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant tree onions in Dover is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant tree onions and expect a good harvest is probably August. Any later than that and your tree onions may not have a chance to really do well. Starting your tree onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Dover. In the coldest months of winter you can expect an average low temperature of 0°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Dover and it will vary from year to year. Half of the time in Dover you get a frost after April 15 so make sure that you are ready to protect your tree onions if you have a surprise late frost.

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.