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.

A common way of making a decision about when you can plant hardy hibiscus is to use the USDA zone info for Helena.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since hardy hibiscus are very cold tolerant you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hardy hibiscus in Helena is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant hardy hibiscus and expect a good harvest is probably September. Any later than that and your hardy hibiscus may not have a chance to really do well. Starting your hardy hibiscus indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Helena. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Helena is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Helena it frosts late in the year after March 15 so make sure that you are ready to cover your hardy hibiscus if you have one of those late frosts.

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.