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.

By reviewing the USDA zone info for Helena you should be able to figure out when it's possible to plant daylily.

Planting Calendar for Daylily

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

Since daylily are one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant daylily 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 daylily and expect a good harvest is probably September. 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 couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Helena. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Helena is just an average the actual date of last frost will vary from year to year. Half of the time in Helena it frosts late in the year after March 15 so just be sure to be ready to protect your daylily in the event of one of those late frosts.

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.