One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to determine when you can plant tithonia by looking at the USDA zone info for Monmouth.

Planting Calendar for Tithonia

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

It's not a good idea to plant tithonia until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant tithonia in Monmouth 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 really do well. If you are starting your tithonia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Monmouth the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Monmouth and it changes from year to year. Half of the time in Monmouth you get surprised by a frost after March 15 so make sure that you are prepared to cover your tithonia if you have one of those late frosts.

USDA Zone Info for Monmouth

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Monmouth

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