One of the first steps you take when you are making a decision about 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 Helena can be used to determine when it's a good idea to plant fountain grass.

Planting Calendar for Fountain Grass

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

Since fountain grass do ok in moderate cold you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant fountain grass in Helena 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 fountain grass and expect a good harvest is probably August. You probably don't want to wait any later than that or else your fountain grass may not have a chance to really do well. You can get started a little bit earlier by starting your fountain grass indoors.

Last Frost Date

The average date of last frost is May 15 in Helena. You should expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for Helena is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Helena there is a last frost after May 15 be ready to cover your fountain grass if you have one of those late frosts.

USDA Zone Info for Helena

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Helena

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