One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

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

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 tells us that you can get them planted earlier than other frost tender plants.

The earliest that you can plant helianthemum in Terre Haute 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. If you are starting your helianthemum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Terre Haute. 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 Terre Haute is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Terre Haute you get a frost after April 15 so make sure that you are prepared to cover your helianthemum in the event of a surprise late frost.

USDA Zone Info for Terre Haute

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 Terre Haute

You may be interested in your other planting guides for Terre Haute.