One of the first steps you take when you are estimating 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 will be able to estimate when to plant bittercress by looking at the USDA zone info for Thornton.

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 do well in mild cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant bittercress in Thornton 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. 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

On average all chance of frost has passed is on April 15 in Thornton. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Thornton may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Thornton last frost occurs after April 15 be ready to protect your bittercress in the event of one of those late frosts.

USDA Zone Info for Thornton

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Thornton

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