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

A common way of estimating when it's possible to plant helianthemum is to examine the USDA zone info for Marietta.

Planting Calendar for Helianthemum

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

Helianthemum tend to make it in a little bit of cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Marietta 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 really do well. 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

In Marietta the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -5°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Marietta and it changes from year to year. Half of the time in Marietta you get surprised by a frost after April 15 so just be sure to be ready to cover your helianthemum in the event of a surprise late frost.

USDA Zone Info for Marietta

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Marietta

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