One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Zone 1a can be reffered to in order to figure out when to plant larkspur.

Planting Calendar for Larkspur

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

Larkspur do well in cold which means that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant larkspur in Zone 1a is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant larkspur and expect a good harvest is probably July. You probably don't want to wait any later than that or else 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

In Zone 1a the average date of last frost happens on June 15. You should expect an average low temperature of -60°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 1a may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 1a you get surprised by a frost after June 15 be ready to cover your larkspur if you have one of those late frosts.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-60°F
Highest Expected Low	-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in your other planting guides for Zone 1a.