One of the best tools that you have as gardeners to help us figure out 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.

The first chance to plant welsh onion in Ames 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.

You can plant welsh onion slightly earlier in the year because they are barely cold tolerant.

The earliest that you can plant welsh onion in Ames 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 few weeks earlier by starting your welsh onion indoors.

Last Frost Date

The average date of last frost is April 15 in Ames. You should expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Ames and it is different every year. Half of the time in Ames 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 one of those late frosts.

USDA Zone Info for Ames

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Ames

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