One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant pentas in Duluth should be figured out by using the USDA zone info.

Planting Calendar for Pentas

Frost tolerance for pentas:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since pentas require warm weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant pentas in Duluth is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant pentas and expect a good harvest is probably August. If you wait any later than that and your pentas may not have a chance to grow to maturity. Starting your pentas indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Duluth. It might get as low as -30°F during the coldest months of winter.

It's important to remember that USDA zone info for Duluth is just an average and the actual date of last frost changes from year to year. Half of the time in Duluth you get a frost after May 15 so be sure to be ready to protect your pentas if you have a late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Duluth

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