One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of making a decision about when it's possible to plant tithonia is to examine the USDA zone info for Humboldt.

Planting Calendar for Tithonia

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

Since tithonia require warm weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant tithonia in Humboldt 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 grow to maturity. If you are starting your tithonia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Humboldt the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Humboldt is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Humboldt it frosts late in the year after April 15 be ready to protect your tithonia if you have a late frost.

USDA Zone Info for Humboldt

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 Humboldt

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