One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when you can plant larkspur is to use the USDA zone info for Coralville.

Planting Calendar for Larkspur

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

You can plant larkspur a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant larkspur in Coralville is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant larkspur and expect a good harvest is probably September. Any later than that and your larkspur may not have a chance to fully mature. Starting your larkspur indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Coralville. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Coralville is an average and the actual date of last frost will vary from year to year. Half of the time in Coralville you get surprised by a frost after April 15 so always be ready to protect your larkspur if you have a surprise late frost.

USDA Zone Info for Coralville

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Coralville

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