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.

The first opportunity to plant tithonia in Roma can be figured out by using the USDA zone info.

Planting Calendar for Tithonia

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

You should not plant tithonia until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant tithonia 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 tithonia and expect a good harvest is probably September. If you wait any later than that and your tithonia may not have a chance to really do well. You can get started a little bit earlier by starting your tithonia indoors.

Last Frost Date

In Roma the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Roma is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Roma last frost occurs after February 15 be ready to cover your tithonia in the event of a surprise 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.