One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of estimating when it's the best time to plant bells of ireland is to check out the USDA zone info for Helena.

Planting Calendar for Bells of Ireland

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

Bells of Ireland can survive in a tiny bit of cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

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

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Helena and it is different every year. Half of the time in Helena there is a last frost after May 15 so make sure that you are ready to cover your bells of ireland if you have 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.