Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when to plant steirodiscus in Helena by using the USDA zone info.

Planting Calendar for Steirodiscus

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

Since steirodiscus do ok in moderate cold you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant steirodiscus 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 steirodiscus and expect a good harvest is probably August. If you wait any later than that and your steirodiscus may not have a chance to fully mature. Starting your steirodiscus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Helena the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Remember that USDA zone info for Helena is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Helena last frost occurs after May 15 so make sure that you are ready to protect your steirodiscus in the event of 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.