Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Rexburg it's possible to estimate when 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 moderate cold which means that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant helianthemum in Rexburg 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. Starting your helianthemum indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Rexburg is an average the actual date of last frost will vary from year to year. Since half of the time in Rexburg it frosts late in the year after April 15 be ready to protect your helianthemum if you have a surprise late frost.

USDA Zone Info for Rexburg

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 Rexburg

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