One of the first steps you take when you are making a decision about 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.

A way of estimating when it's the best time to plant trachelium is to use the USDA zone info for Ottawa.

Planting Calendar for Trachelium

Frost tolerance for trachelium:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since trachelium are not cold tolerant you need to wait until after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ottawa. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ottawa and it changes from year to year. Since half of the time in Ottawa last frost occurs after April 15 be ready to cover your trachelium 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.