Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant tithonia in Ottawa should be figured out by referring to the USDA zone info.

Planting Calendar for Tithonia

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

Tithonia require warm weather which means that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

In Ottawa the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Ottawa and it is different every year. Half of the time in Ottawa you get surprised by a frost after April 15 so be sure to be ready to protect your tithonia in the event of one of those late frosts.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ottawa

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