One of the first steps you take when you are getting a good idea 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.

In Gretna you can estimate when it's a good idea to plant ageratum by using the USDA zone info.

Planting Calendar for Ageratum

Frost tolerance for ageratum:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Ageratum do not do well in cold weather which tells us that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant ageratum in Gretna is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant ageratum and expect a good harvest is probably September. Any later than that and your ageratum may not have a chance to really do well. You can get started a few weeks earlier by starting your ageratum indoors.

Last Frost Date

On average the last frost has passed is on 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. Since half of the time in Gretna last frost occurs after February 15 be ready to cover your ageratum if you have one of those late frosts.

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.