Before planting it is a good idea to find your USDA Zone info to determine your garden 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 Kennewick can be reffered to in order to determine when to plant tithonia.

Planting Calendar for Tithonia

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

It's a bad idea to plant tithonia until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant tithonia in Kennewick 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. If you wait 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Kennewick. It might get as low as 0°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Kennewick is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Kennewick it frosts late in the year after April 15 be ready to cover your tithonia in the event of a late frost.

USDA Zone Info for Kennewick

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Kennewick

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