When to Plant Ornamental Grasses in Lewistown, MT

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.

By using the USDA zone info for Lewistown it's possible to figure out when it's possible to plant ornamental grasses.


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 a bit earlier in the year because they do ok in moderate cold.

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 Lewistown 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 ornamental grasses and expect a good harvest is probably August. Any later than that and your ornamental grasses may not have a chance to fully mature. Starting your ornamental grasses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Lewistown. In the coldest months of winter you can expect an average low temperature of -30°F.

Since the USDA zone info for Lewistown is just an average the actual date of last frost changes from year to year. Half of the time in Lewistown you get a frost after May 15 so just be sure to be ready to protect your ornamental grasses if you have one of those late frosts.

USDA Zone Info for Lewistown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-30°F
Highest Expected Low-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Lewistown

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