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

You can estimate when to plant onions in Riverdale by referring to the USDA zone info.

Planting Calendar for Onions

Frost tolerance for onions:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Onions do well in pretty solid cold which means that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant onions in Riverdale is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably September. If you wait any later than that and your onions may not have a chance to fully mature. Starting your onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on March 15 in Riverdale. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Riverdale is not always accurate the actual date of last frost is different every year. Half of the time in Riverdale it frosts late in the year after March 15 so be sure to be ready to protect your onions in the event of one of those late frosts.

USDA Zone Info for Riverdale

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Riverdale

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