One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

By checking out the USDA zone info for Dover you should be able to estimate when it's possible to plant tithonia.

Planting Calendar for Tithonia

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

Since tithonia are not cold tolerant you have to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant tithonia in Dover 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 fully mature. 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

On average the last frost when the weather gets warmer is on April 15 in Dover. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Dover is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Dover it frosts late in the year after April 15 so be sure to be ready to protect your tithonia in the event of a surprise late frost.

USDA Zone Info for Dover

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 Dover

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