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 a good idea to figure out when it's a good idea to plant onions by referring to the USDA zone info for Harrisburg.

Planting Calendar for Onions

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

Onions do ok in cold weather which means that you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant onions in Harrisburg 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 grow to maturity. You can get started a little bit earlier by starting your onions indoors.

Last Frost Date

In Harrisburg the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

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

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Harrisburg

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