One of the first steps you take when you are determining 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 first opportunity to plant hemerocallis in Ottawa should be estimated by checking out the USDA zone info.

Planting Calendar for Hemerocallis

Frost tolerance for hemerocallis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Hemerocallis can survive in a little bit of cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant hemerocallis 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 hemerocallis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hemerocallis may not have a chance to really do well. If you are starting your hemerocallis indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Ottawa the average date of last frost happens on April 15. 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 changes from year to year. Half of the time in Ottawa last frost occurs after April 15 so just be sure to be ready to protect your hemerocallis if you have a surprise late frost.

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.