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.

You can determine when to plant tree onions in Charles Town by referring to 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.

Tree onions do ok in moderate cold which tells us that you can start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant tree onions in Charles Town 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. You probably don't want to wait any later than that or else your tree onions may not have a chance to really do well. If you are starting your tree onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Charles Town. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for Charles Town is just an average and the actual date of last frost will vary from year to year. Half of the time in Charles Town it frosts late in the year after April 15 so be sure to be ready to protect your tree onions in the event of a surprise late frost.

USDA Zone Info for Charles Town

Here is the info for USDA Zone 6b.

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

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Charles Town

You may be interested in your other planting guides for Charles Town.