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 USDA zone info for Powell can be looked at to determine when it's the best time to plant helianthemum.

Planting Calendar for Helianthemum

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

Helianthemum can survive in mild cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Powell 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 really do well. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

The average date of last frost is April 15 in Powell. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Powell is just an average and the actual date of last frost changes from year to year. Half of the time in Powell last frost occurs after April 15 so just be sure to be ready to cover your helianthemum if you have a surprise late frost.

USDA Zone Info for Powell

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Powell

You may be interested in your other planting guides for Powell.