Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's a good idea to plant helianthemum is to refer to the USDA zone info for Slinger.

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 are moderately cold tolerant.

The earliest that you can plant helianthemum in Slinger 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 fully mature. 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 Slinger. It might get as low as -20°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Slinger and it can change quite a bit from year to year. Half of the time in Slinger it frosts late in the year after April 15 so just be sure to be ready to cover your helianthemum if you have a late frost.

USDA Zone Info for Slinger

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 Slinger

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