One of the first steps you take when you are determining 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.

The best time to plant welsh onion in Southampton can be estimated by using the USDA zone info.

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 barely cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant welsh onion in Southampton 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 really do well. Starting your welsh onion indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Southampton and it can change quite a bit from year to year. Half of the time in Southampton it frosts late in the year after April 15 so always be ready to protect your welsh onion if you have one of those late frosts.

USDA Zone Info for Southampton

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 Southampton

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