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.

The USDA zone info for Ridgefield should be looked at to figure out when it's a good idea to plant onions.

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 cold which tells us that you can get them planted much earlier than other frost tender plants.

The earliest that you can plant onions in Ridgefield 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. You probably don't want to wait any later than that or else your onions may not have a chance to fully mature. Starting your onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Ridgefield. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Ridgefield is not always accurate the actual date of last frost is different every year. Half of the time in Ridgefield it frosts late in the year after March 15 so always be ready to cover your onions in the event of a surprise late frost.

USDA Zone Info for Ridgefield

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 Ridgefield

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