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.

The USDA zone info for Roselle can be looked at to figure out when to plant tithonia.

Planting Calendar for Tithonia

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

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

The earliest that you can plant tithonia in Roselle is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant tithonia and expect a good harvest is probably August. Any later than that and your tithonia may not have a chance to grow to maturity. If you are starting your tithonia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Roselle. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Roselle is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Roselle you get a frost after April 15 be ready to protect your tithonia if you have a surprise late frost.

USDA Zone Info for Roselle

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Roselle

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