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.

You can determine when to plant helianthemum in Twin Falls by reviewing the USDA zone info.

Planting Calendar for Helianthemum

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

Helianthemum are moderately cold tolerant which means that you can get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant helianthemum in Twin Falls 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 helianthemum and expect a good harvest is probably September. Any later than that and your helianthemum may not have a chance to grow to maturity. If you are starting your helianthemum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Twin Falls the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Twin Falls may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Twin Falls you get surprised by a frost after April 15 so be sure to be ready to cover your helianthemum in the event of one of those late frosts.

USDA Zone Info for Twin Falls

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Twin Falls

You may be interested in your other planting guides for Twin Falls.