When to Plant Onions in Mountainside, NJ

Before planting it is a good idea to find your USDA Zone info to figure out 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.

You can determine when it's the best time to plant onions in Mountainside by looking at 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 quite a bit earlier in the year than other plants that might not handle the cold.

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 Mountainside 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 really do well. You can get started a few weeks earlier by starting your onions indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Mountainside. In the coldest months of winter you can expect an average low temperature of 0°F.

Keep in mind that USDA zone info for Mountainside may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Mountainside last frost occurs after April 15 so make sure that you are ready to cover your onions if you have one of those late frosts.

USDA Zone Info for Mountainside

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low0°F
Highest Expected Low5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Mountainside

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