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

You can figure out when it's possible to plant larkspur in Idaho Falls by reviewing 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 plants that are more sensitive to the cold.

The earliest that you can plant larkspur in Idaho Falls 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. You probably don't want to wait any later than that or else your larkspur may not have a chance to grow to maturity. Starting your larkspur indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Idaho Falls. It might get as low as -20°F during the coldest months of winter.

Remember that USDA zone info for Idaho Falls is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Idaho Falls you get surprised by a frost after April 15 so make sure that you are ready to cover your larkspur in the event of a surprise late frost.

USDA Zone Info for Idaho Falls

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 Idaho Falls

You may be interested in your other planting guides for Idaho Falls.