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.

A way of getting a good idea when it's the best time to plant tithonia is to look at the USDA zone info for Delta.

Planting Calendar for Tithonia

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

Since tithonia are not cold tolerant you have to wait until after all chance of frost has passed before you can plant them.

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Delta. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Delta and it can change quite a bit from year to year. Half of the time in Delta you get a frost after April 15 so make sure that you are prepared to cover your tithonia if you have a late frost.

USDA Zone Info for Delta

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 Delta

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