The USDA Zone info is a great tool for gardeners to help us estimate 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.

The USDA zone info for Pullman should be reffered to in order to estimate when you can plant tithonia.

Planting Calendar for Tithonia

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

Tithonia are not cold tolerant which tells us that it's important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant tithonia in Pullman 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. Starting your tithonia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Pullman. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Pullman is an average the actual date of last frost is different every year. Half of the time in Pullman you get surprised by a frost after April 15 so make sure that you are ready to protect your tithonia in the event of a surprise late frost.

USDA Zone Info for Pullman

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Pullman

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