When to Plant Ornamental Grasses in Thornton, CO

One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant ornamental grasses in Thornton can be determined by using the USDA zone info.


Planting Calendar for Ornamental Grasses

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

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant ornamental grasses
Possibly ok, but a risky time to plant ornamental grasses
Probably not a good time to plant ornamental grasses

The earliest that you can plant ornamental grasses 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 ornamental grasses and expect a good harvest is probably August. Any later than that and your ornamental grasses may not have a chance to really do well. Starting your ornamental grasses indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Thornton the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Thornton is an average the actual date of last frost changes from year to year. Since half of the time in Thornton you get surprised by a frost after April 15 be ready to cover your ornamental grasses in the event of a 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.