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 Morrison should be reffered to in order 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.

You can plant helianthemum just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant helianthemum in Morrison 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. You probably don't want to wait any later than that or else your helianthemum may not have a chance to fully mature. Starting your helianthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Morrison the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Morrison may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Morrison last frost occurs after April 15 be ready to cover your helianthemum if you have a late frost.

USDA Zone Info for Morrison

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Morrison

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