The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Renton you can determine when it's a good idea to plant tithonia by looking at the USDA zone info.

Planting Calendar for Tithonia

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

It's probably not a good idea to plant tithonia until after the last frost has passed because they require warm weather.

The earliest that you can plant tithonia in Renton 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 fully mature. Starting your tithonia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Renton may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Renton last frost occurs after March 15 be ready to cover your tithonia in the event of one of those late frosts.

USDA Zone Info for Renton

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Renton

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