Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to figure out when to plant onions by reviewing the USDA zone info for Chelsea.

Planting Calendar for Onions

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

Onions tend to make it in a bit of cold which means that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant onions in Chelsea 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. Any later than that and your onions may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your onions indoors.

Last Frost Date

The average date of last frost is April 15 in Chelsea. You can expect an average low temperature of -5°F in the coldest months of winter.

Always keep in mind that USDA zone info for Chelsea is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Chelsea you get a frost after April 15 be ready to cover your onions if you have a surprise late frost.

USDA Zone Info for Chelsea

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Chelsea

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