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.

In Hillsboro you can estimate when it's the best time to plant bunching onions by using 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.

Since bunching onions are barely cold tolerant you can plant them a bit earlier in the year than other plants that might not handle the 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 fully mature. Starting your bunching onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Hillsboro. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Hillsboro is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Hillsboro there is a last frost after March 15 be ready to protect your bunching onions if you have one of those late frosts.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Hillsboro

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