One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant helianthemum in Gretna can be determined by looking at the USDA zone info.

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 Gretna is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant helianthemum and expect a good harvest is probably October. Any later than that and your helianthemum may not have a chance to grow to maturity. Starting your helianthemum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Gretna. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Gretna may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Gretna you get surprised by a frost after February 15 so make sure that you are prepared to protect your helianthemum if you have a late frost.

USDA Zone Info for Gretna

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Gretna

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