One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 Ottawa should be looked at to determine when it's the best time to plant chervil.

Planting Calendar for Chervil

Frost tolerance for chervil:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Chervil tend to make it in a tiny bit of cold which means that you can plant them just a tiny bit earlier in the year than more sensitive plants.

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

The last month that you can plant chervil and expect a good harvest is probably August. You probably don't want to wait any later than that or else your chervil may not have a chance to fully mature. Starting your chervil indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Ottawa 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.

Since the USDA zone info for Ottawa is not always accurate the actual date of last frost changes from year to year. Half of the time in Ottawa you get surprised by a frost after April 15 so just be sure to be ready to cover your chervil in the event of a 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.