Before planting it is a good idea to find your USDA Zone info to estimate 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.

The earliest that you can plant delphinium in Chisholm should be determined by referring to the USDA zone info.

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 do well in a tiny bit of cold which tells us that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant delphinium in Chisholm 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. Any later than that and your delphinium may not have a chance to fully mature. You can get started a few weeks earlier by starting your delphinium indoors.

Last Frost Date

On average the last frost is on May 15 in Chisholm. It might get as low as -35°F during the coldest months of winter.

Since the USDA zone info for Chisholm is an average the actual date of last frost changes from year to year. Since half of the time in Chisholm it frosts late in the year after May 15 be ready to protect your delphinium in the event of a surprise late frost.

USDA Zone Info for Chisholm

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 Chisholm

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