The USDA Zone info is a great tool for gardeners to help us determine 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.

By looking at the USDA zone info for Helena you should be able to estimate when to plant brachycome.

Planting Calendar for Brachycome

Frost tolerance for brachycome:	Not tolerant of frost.
When to plant:	After the last frost.

Since brachycome are not cold tolerant you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant brachycome 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 brachycome and expect a good harvest is probably August. You probably don't want to wait any later than that or else your brachycome may not have a chance to fully mature. You can get started a little bit earlier by starting your brachycome indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Helena is an average and the actual date of last frost changes from year to year. Since half of the time in Helena you get surprised by a frost after May 15 be ready to protect your brachycome in the event of a 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.