One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

You will be able to estimate when it's a good idea to plant ageratum by referring to the USDA zone info for Port Arthur.

Planting Calendar for Ageratum

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

Since ageratum require warm weather it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant ageratum in Port Arthur 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 fully mature. If you are starting your ageratum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Port Arthur. In the coldest months of winter you should expect an average low temperature of 20°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Port Arthur and it can change quite a bit from year to year. Half of the time in Port Arthur last frost occurs after February 15 so always be ready to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for Port Arthur

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Port Arthur

You may be interested in your other planting guides for Port Arthur.