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.

One way of determining when it's the best time to plant delphinium is to consult the USDA zone info for Bemidji.

Planting Calendar for Delphinium

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

Delphinium are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant delphinium in Bemidji 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 delphinium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your delphinium may not have a chance to grow to maturity. Starting your delphinium indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Bemidji the average date of last frost happens on May 15. It might get as low as -35°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Bemidji is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Bemidji it frosts late in the year after May 15 so be sure to be ready to cover your delphinium in the event of a surprise late frost.

USDA Zone Info for Bemidji

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Bemidji

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