The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when you can plant tithonia in Douglas by referring to 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.

Tithonia are not cold tolerant which means that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant tithonia in Douglas is May. However, you really should wait until June 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 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 Douglas the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Douglas is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Douglas there is a last frost after May 15 be ready to protect your tithonia if you have a late frost.

USDA Zone Info for Douglas

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Douglas

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