When to Plant Onions in Manchester, NH

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of figuring out when it's the best time to plant onions is to consult the USDA zone info for Manchester.


Planting Calendar for Onions

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

You can plant onions a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant onions
Possibly ok, but a risky time to plant onions
Probably not a good time to plant onions

The earliest that you can plant onions in Manchester 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 really do well. Starting your onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Manchester the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that USDA zone info for Manchester is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Manchester you get surprised by a frost after April 15 so just be sure to be ready to protect your onions in the event of a surprise late frost.

USDA Zone Info for Manchester

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°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 -10°F.

Plants to Grow in Manchester

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