One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. 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 estimate when to plant welsh onion by checking out 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.

You can plant welsh onion just a tiny bit earlier in the year because they are barely cold tolerant.

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. Any later than that and your welsh onion may not have a chance to fully mature. Starting your welsh onion indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Henderson. You can expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for Henderson is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Henderson it frosts late in the year after March 15 so just be sure to be ready to cover your welsh onion if you have a surprise late frost.

USDA Zone Info for Henderson

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Henderson

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