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.

The best time to plant welsh onion in Hampshire can be estimated by referring to 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.

Welsh onion are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant welsh onion in Hampshire 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 grow to maturity. You can get started a little bit earlier by starting your welsh onion indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Hampshire. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Hampshire is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Hampshire you get surprised by a frost after April 15 so make sure that you are ready to cover your welsh onion in the event of a late frost.

USDA Zone Info for Hampshire

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Hampshire

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