One of the first steps you take when you are determining your gardening schedule is find your 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.

You will be able to figure out when it's a good idea to plant helianthemum by checking out the USDA zone info for Bolingbrook.

Planting Calendar for Helianthemum

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

Since helianthemum do well in moderate cold you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Bolingbrook 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 grow to maturity. Starting your helianthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Bolingbrook and it is different every year. Since half of the time in Bolingbrook last frost occurs after April 15 be ready to protect your helianthemum in the event of a late frost.

USDA Zone Info for Bolingbrook

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 Bolingbrook

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