One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Roosevelt can be used to estimate when it's a good idea 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 are moderately cold tolerant which tells us that you can get them planted earlier than other frost tender plants.

The earliest that you can plant helianthemum in Roosevelt 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. Starting your helianthemum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Roosevelt the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Roosevelt is an average and the actual date of last frost changes from year to year. Since half of the time in Roosevelt there is a last frost after April 15 be ready to protect your helianthemum in the event of a late frost.

USDA Zone Info for Roosevelt

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Roosevelt

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