The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Helena should be reffered to in order to determine when you can plant mimulus.

Planting Calendar for Mimulus

Frost tolerance for mimulus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since mimulus do not do well in cold weather it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant mimulus 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 mimulus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your mimulus may not have a chance to really do well. Starting your mimulus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Helena the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 10°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Helena and it will vary from year to year. Half of the time in Helena you get surprised by a frost after March 15 so be sure to be ready to cover your mimulus in the event of a late frost.

USDA Zone Info for Helena

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Helena

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