The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Duluth you can estimate when it's a good idea to plant bidens by checking out the USDA zone info.

Planting Calendar for Bidens

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

Bidens require warm weather which means that it is important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

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

Last Frost Date

In Duluth the average date of last frost happens on April 15. You can expect an average low temperature of 5°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Duluth and it changes from year to year. Since half of the time in Duluth you get surprised by a frost after April 15 be ready to protect your bidens in the event of one of those late frosts.

USDA Zone Info for Duluth

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 Duluth

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