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.

In Ottawa you can determine when to plant tritoma by using the USDA zone info.

Planting Calendar for Tritoma

Frost tolerance for tritoma:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Tritoma can survive in quite a bit of cold which tells us that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant tritoma in Ottawa is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant tritoma and expect a good harvest is probably September. Any later than that and your tritoma may not have a chance to grow to maturity. If you are starting your tritoma indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Ottawa is just an average the actual date of last frost will vary from year to year. Half of the time in Ottawa you get a frost after April 15 so be sure to be ready to cover your tritoma in the event of one of those late frosts.

USDA Zone Info for Ottawa

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 Ottawa

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