One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Hillsboro you will be able to estimate when it's possible to plant monarda.

Planting Calendar for Monarda

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

Monarda are barely cold tolerant which tells us that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant monarda 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 monarda and expect a good harvest is probably August. If you wait any later than that and your monarda may not have a chance to really do well. Starting your monarda indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Hillsboro. You should expect an average low temperature of 10°F in the coldest months of winter.

It's important to remember that USDA zone info for Hillsboro is not always accurate and the actual date of last frost is different every year. Half of the time in Hillsboro there is a last frost after March 15 so make sure that you are prepared to cover your monarda if you have a late frost.

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.