Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's the best time to plant tithonia in Oelwein by reviewing the USDA zone info.

Planting Calendar for Tithonia

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

Since tithonia require warm weather you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant tithonia in Oelwein 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. You probably don't want to wait any later than that or else 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 is on April 15 in Oelwein. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Oelwein is just an average the actual date of last frost is different every year. Since half of the time in Oelwein last frost occurs after April 15 be ready to cover your tithonia if you have a late frost.

USDA Zone Info for Oelwein

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oelwein

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