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.

The earliest that you can plant larkspur in Flagstaff can be estimated by checking out 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.

Larkspur do well in quite a bit of cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant larkspur in Flagstaff 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. If you wait any later than that and your larkspur may not have a chance to really do well. Starting your larkspur indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Flagstaff the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Flagstaff and it is different every year. Half of the time in Flagstaff you get surprised by a frost after April 15 so always be ready to cover your larkspur in the event of a surprise late frost.

USDA Zone Info for Flagstaff

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Flagstaff

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