One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when you can plant helianthemum by checking out the USDA zone info for De Witt.

Planting Calendar for Helianthemum

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

Helianthemum are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than more sensitive plants.

The earliest that you can plant helianthemum in De Witt 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. If you wait 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

In De Witt the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Just be sure to remember that USDA zone info for De Witt is just an average and the actual date of last frost is different every year. Half of the time in De Witt you get surprised by a frost after April 15 so be sure to be ready to cover your helianthemum in the event of a surprise late frost.

USDA Zone Info for De Witt

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 De Witt

You may be interested in your other planting guides for De Witt.