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

It's a good idea to estimate when it's possible to plant welsh onion by using the USDA zone info for Charlestown.

Planting Calendar for Welsh onion

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

Since welsh onion are one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant welsh onion in Charlestown 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 welsh onion and expect a good harvest is probably August. Any later than that and your welsh onion may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your welsh onion indoors.

Last Frost Date

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

Since the USDA zone info for Charlestown may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Charlestown there is a last frost after April 15 so just be sure to be ready to cover your welsh onion in the event of one of those late frosts.

USDA Zone Info for Charlestown

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 Charlestown

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