One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant welsh onion in Petersburg should be determined by looking at 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.

You can plant welsh onion just a tiny bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant welsh onion in Petersburg 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 fully mature. You can get started a few weeks earlier by starting your welsh onion indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Petersburg. In the coldest months of winter you can expect an average low temperature of 5°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Petersburg and it changes from year to year. Half of the time in Petersburg you get a frost after April 15 so always be ready to cover your welsh onion in the event of one of those late frosts.

USDA Zone Info for Petersburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Petersburg

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