One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Helena you should be able to estimate when you can plant cerastium.

Planting Calendar for Cerastium

Frost tolerance for cerastium:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since cerastium are moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant cerastium 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 cerastium and expect a good harvest is probably September. Any later than that and your cerastium may not have a chance to grow to maturity. Starting your cerastium indoors is a great way to get them started a little bit 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.

Always keep in mind that USDA zone info for Helena may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Helena you get a frost after March 15 so be sure to be ready to protect your cerastium if you have a surprise 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.