The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Summerville you will be able to figure out when it's a good idea to plant welsh onion.

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 do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant welsh onion in Summerville 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. If you wait any later than that and your welsh onion may not have a chance to fully mature. You can get started a little bit earlier by starting your welsh onion indoors.

Last Frost Date

The average date of last frost is March 15 in Summerville. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Summerville is just an average the actual date of last frost will vary from year to year. Since half of the time in Summerville there is a last frost after March 15 be ready to cover your welsh onion if you have a surprise late frost.

USDA Zone Info for Summerville

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Summerville

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