One of the first steps you take when you are estimating your gardening schedule is find your 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 USDA zone info for South Portland can be read to figure out when you can plant tithonia.

Planting Calendar for Tithonia

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

It's not a good idea to plant tithonia until after all chance of frost has passed because they require warm weather.

The earliest that you can plant tithonia in South Portland 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. You probably don't want to wait any later than that or else 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 little bit earlier.

Last Frost Date

In South Portland the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for South Portland and it can change quite a bit from year to year. Half of the time in South Portland it frosts late in the year after April 15 so always be ready to protect your tithonia if you have one of those late frosts.

USDA Zone Info for South Portland

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 South Portland

You may be interested in your other planting guides for South Portland.