One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Superior you can determine when it's possible to plant larkspur by looking at the USDA zone info.

Planting Calendar for Larkspur

Frost tolerance for larkspur:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since larkspur do well in cold you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant larkspur in Superior 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 larkspur and expect a good harvest is probably August. You probably don't want to wait any later than that or else your larkspur may not have a chance to fully mature. You can get started a few weeks earlier by starting your larkspur indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Superior. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Superior is just an average and the actual date of last frost is different every year. Half of the time in Superior you get a frost after May 15 so make sure that you are ready to cover your larkspur in the event of a late frost.

USDA Zone Info for Superior

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Superior

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