The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to determine when to plant helianthemum by reviewing the USDA zone info for Wheaton.

Planting Calendar for Helianthemum

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

Helianthemum do well in a little bit of cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Wheaton 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 couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Wheaton. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Wheaton is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Wheaton there is a last frost after April 15 be ready to cover your helianthemum if you have one of those late frosts.

USDA Zone Info for Wheaton

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 Wheaton

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