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.

You should be able to estimate when it's a good idea to plant bittercress by using the USDA zone info for Superior.

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.

You can plant bittercress a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant bittercress in Superior is April. However, you really should wait until May 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. Any later than that and your bittercress may not have a chance to grow to maturity. You can get started a little bit earlier by starting your bittercress indoors.

Last Frost Date

The average date of last frost is May 15 in Superior. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Superior 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 Superior there is a last frost after May 15 so make sure that you are prepared to cover your bittercress in the event of one of those late frosts.

USDA Zone Info for Superior

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Superior

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