One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Ottawa should be used to determine when it's possible to plant gayfeather.

Planting Calendar for Gayfeather

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

Gayfeather do well in cold which means that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant gayfeather 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 gayfeather and expect a good harvest is probably September. You probably don't want to wait any later than that or else your gayfeather may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your gayfeather indoors.

Last Frost Date

In Ottawa the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for Ottawa is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Ottawa it frosts late in the year after April 15 so be sure to be ready to protect your gayfeather if you have 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.