When to Plant Ornamental Grasses in Great Falls, MT

One of the first steps you take when you are getting a good idea 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 earliest that you can plant ornamental grasses in Great Falls should be determined by reviewing 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.

Ornamental Grasses tend to make it in mild cold which means that you can plant them just a tiny bit earlier in the year than other plants that might not handle the 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 Great Falls 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. If you wait any later than that and your ornamental grasses may not have a chance to grow to maturity. If you are starting your ornamental grasses indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Great Falls. It might get as low as -30°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 Great Falls and it is different every year. Half of the time in Great Falls you get a frost after May 15 so make sure that you are prepared to cover your ornamental grasses if you have a surprise late frost.

USDA Zone Info for Great Falls

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 Great Falls

You may be interested in your other planting guides for Great Falls.