The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 estimate when to plant chrysocephalum in Helena by checking out the USDA zone info.

Planting Calendar for Chrysocephalum

Frost tolerance for chrysocephalum:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Chrysocephalum require warm weather which tells us that you need to wait until it warms up after the last frost before you can plant them.

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

The last month that you can plant chrysocephalum and expect a good harvest is probably August. If you wait any later than that and your chrysocephalum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your chrysocephalum indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Helena. It might get as low as -25°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Helena and it changes from year to year. Since half of the time in Helena you get a frost after May 15 be ready to cover your chrysocephalum in the event of a surprise late frost.

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.