Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when you can plant welsh onion by reviewing the USDA zone info for Henderson.

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 start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant welsh onion in Henderson 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 fully mature. If you are starting your welsh onion indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Henderson is just an average the actual date of last frost changes from year to year. Since half of the time in Henderson there is a last frost after April 15 be ready to protect your welsh onion if you have one of those late frosts.

USDA Zone Info for Henderson

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 Henderson

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