One of the first steps you take when you are getting a good idea 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.

In Edwardsville you can determine when to plant helianthemum by reviewing the USDA zone info.

Planting Calendar for Helianthemum

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

Helianthemum are moderately cold tolerant which means that you can get them planted earlier than other frost tender plants.

The earliest that you can plant helianthemum in Edwardsville 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. You can get started a few weeks earlier by starting your helianthemum indoors.

Last Frost Date

The average date of last frost is April 15 in Edwardsville. In the coldest months of winter you should expect an average low temperature of -10°F.

Just be sure to remember that USDA zone info for Edwardsville is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Edwardsville there is a last frost after April 15 be ready to cover your helianthemum in the event of a late frost.

USDA Zone Info for Edwardsville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Edwardsville

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