When to Plant Tithonia in Washington, IA

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

The first opportunity to plant tithonia in Washington should be estimated by reviewing the USDA zone info.

Create beautiful hand-made plants at forever-plants.com

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 tells us that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant tithonia
Possibly ok, but a risky time to plant tithonia
Probably not a good time to plant tithonia

The earliest that you can plant tithonia in Washington 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. You can get started a few weeks earlier by starting your tithonia indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Washington. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Washington and it will vary from year to year. Since half of the time in Washington you get surprised by a frost after April 15 be ready to cover your tithonia if you have a surprise late frost.

USDA Zone Info for Washington

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 Washington

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