One of the best tools that you have as gardeners to help us determine 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.

By using the USDA zone info for Tomball you should be able to determine when it's a good idea to plant lisianthus.

Planting Calendar for Lisianthus

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

Lisianthus require warm weather which tells us that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant lisianthus in Tomball 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. Any later than that and your lisianthus may not have a chance to really do well. You can get started a couple of weeks earlier by starting your lisianthus indoors.

Last Frost Date

In Tomball the average date of last frost happens on February 15. You should expect an average low temperature of 20°F in the coldest months of winter.

Keep in mind that USDA zone info for Tomball is not always accurate and the actual date of last frost is different every year. Half of the time in Tomball there is a last frost after February 15 so always be ready to cover your lisianthus if you have one of those late frosts.

USDA Zone Info for Tomball

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 Tomball

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