One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Thornton can be reviewed to estimate when to plant pampas grass.

Planting Calendar for Pampas Grass

Frost tolerance for pampas grass:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably a bad idea to plant pampas grass until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant pampas grass in Thornton 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 pampas grass and expect a good harvest is probably August. Any later than that and your pampas grass may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your pampas grass indoors.

Last Frost Date

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

Since the USDA zone info for Thornton is not always accurate the actual date of last frost is different every year. Half of the time in Thornton it frosts late in the year after April 15 so be sure to be ready to cover your pampas grass in the event of 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.