The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Roma can be reffered to in order to figure out when it's the best time to plant lisianthus.

Planting Calendar for Lisianthus

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

Lisianthus are not cold tolerant which tells us that you have to 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 Roma 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 really do well. You can get started a couple of weeks earlier by starting your lisianthus indoors.

Last Frost Date

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

Since the USDA zone info for Roma 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 Roma there is a last frost after February 15 be ready to protect your lisianthus if you have a late frost.

USDA Zone Info for Roma

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 Roma

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