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 should be able to figure out when it's possible to plant helianthemum by referring to the USDA zone info for Cleveland.

Planting Calendar for Helianthemum

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

Since helianthemum are moderately cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Cleveland 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 really do well. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

The average date of last frost is March 15 in Cleveland. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Cleveland is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Cleveland there is a last frost after March 15 so make sure that you are ready to protect your helianthemum if you have a late frost.

USDA Zone Info for Cleveland

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Cleveland

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