Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's a good idea to plant larkspur by looking at the USDA zone info for Zone 5a.

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 much earlier in the year than other frost tender plants.

The earliest that you can plant larkspur in Zone 5a 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 grow to maturity. You can get started a little bit earlier by starting your larkspur indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Zone 5a. In the coldest months of winter you should expect an average low temperature of -20°F.

Remember that USDA zone info for Zone 5a is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Zone 5a there is a last frost after April 15 be ready to cover your larkspur if you have a late frost.

USDA Zone Info for Zone 5a

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Zone 5a

You may be interested in your other planting guides for Zone 5a.