One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when it's a good idea to plant lisianthus is to refer to the USDA zone info for Sulphur.

Planting Calendar for Lisianthus

Frost tolerance for lisianthus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Lisianthus do not do well in cold weather which tells us that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant lisianthus in Sulphur 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 lisianthus and expect a good harvest is probably September. If you wait any later than that and your lisianthus may not have a chance to fully mature. Starting your lisianthus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Sulphur the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Sulphur and it can change quite a bit from year to year. Half of the time in Sulphur last frost occurs after February 15 so always be ready to cover your lisianthus in the event of a late frost.

USDA Zone Info for Sulphur

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 Sulphur

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