One of the first steps you take when you are figuring out 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.

The USDA zone info for Thornton should be reviewed to estimate when to plant pincushion flower.

Planting Calendar for Pincushion Flower

Frost tolerance for pincushion flower:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant pincushion flower a little bit earlier in the year because they do well in moderate cold.

The earliest that you can plant pincushion flower in Thornton 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 pincushion flower and expect a good harvest is probably September. You probably don't want to wait any later than that or else your pincushion flower may not have a chance to really do well. You can get started a few weeks earlier by starting your pincushion flower indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Thornton and it is different every year. Half of the time in Thornton it frosts late in the year after April 15 so always be ready to cover your pincushion flower if you have a surprise late frost.

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.