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.

The earliest that you can plant bunching onions in Hillsboro can be estimated by looking at the USDA zone info.

Planting Calendar for Bunching Onions

Frost tolerance for bunching onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant bunching onions slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant bunching onions in Hillsboro is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant bunching onions and expect a good harvest is probably August. Any later than that and your bunching onions may not have a chance to really do well. You can get started a little bit earlier by starting your bunching onions indoors.

Last Frost Date

The average date of last frost is April 15 in Hillsboro. In the coldest months of winter you should expect an average low temperature of -10°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Hillsboro and it can change quite a bit from year to year. Half of the time in Hillsboro last frost occurs after April 15 so make sure that you are prepared to cover your bunching onions if you have a late frost.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 6a.

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

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Hillsboro

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