One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Flagstaff you will be able to figure out when you can plant bittercress.

Planting Calendar for Bittercress

Frost tolerance for bittercress:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bittercress are barely cold tolerant which tells us that you can get them planted just a bit earlier than more sensitive plants.

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

The last month that you can plant bittercress and expect a good harvest is probably August. If you wait any later than that and your bittercress may not have a chance to really do well. You can get started a couple of weeks earlier by starting your bittercress indoors.

Last Frost Date

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

Since the USDA zone info for Flagstaff may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Flagstaff you get surprised by a frost after April 15 so always be ready to protect your bittercress if you have 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.