The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant daylily in Helena should be estimated by referring to the USDA zone info.

Planting Calendar for Daylily

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

Daylily do well in moderate cold which tells us that you can plant them earlier than other plants that might not handle the cold.

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

Last Frost Date

The average date of last frost is May 15 in Helena. In the coldest months of winter you can expect an average low temperature of -25°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year 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 daylily 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.