The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Rowlett can be looked at to figure out when you can plant helianthemum.

Planting Calendar for Helianthemum

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

Helianthemum are one of those plants that can tolerate a little bit of cold weather which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant helianthemum in Rowlett 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 little bit earlier.

Last Frost Date

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

Since the USDA zone info for Rowlett is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Rowlett you get surprised by a frost after March 15 so make sure that you are prepared to protect your helianthemum in the event of a late frost.

USDA Zone Info for Rowlett

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 Rowlett

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