One of the first steps you take when you are estimating 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.

A way of figuring out when it's possible to plant helianthemum is to refer to the USDA zone info for Madison.

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 Madison 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 really do well. If you are starting your helianthemum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Madison. In the coldest months of winter you can expect an average low temperature of 5°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Madison and it is different every year. Half of the time in Madison there is a last frost after April 15 so make sure that you are prepared to protect your helianthemum if you have one of those late frosts.

USDA Zone Info for Madison

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Madison

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