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 first chance to plant welsh onion in Baltimore can be estimated 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.

Welsh onion do ok in mild cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant welsh onion in Baltimore 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. You probably don't want to wait any later than that or else your welsh onion may not have a chance to grow to maturity. If you are starting your welsh onion indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Baltimore. It might get as low as 5°F during the coldest months of winter.

Keep in mind that USDA zone info for Baltimore is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Baltimore it frosts late in the year 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 Baltimore

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 Baltimore

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