Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Helena you can estimate when it's the best time to plant sedum by looking at the USDA zone info.

Planting Calendar for Sedum

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

You can plant sedum a lot earlier in the year because they are very cold tolerant.

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

The last month that you can plant sedum and expect a good harvest is probably August. Any later than that and your sedum may not have a chance to grow to maturity. Starting your sedum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Helena. You can expect an average low temperature of -25°F in the coldest months of winter.

Remember that USDA zone info for Helena is an average and the actual date of last frost will vary from year to year. Since half of the time in Helena you get a frost after May 15 be ready to cover your sedum 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.