Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 Toronto can be reviewed to determine when it's a good idea to plant alternanthera.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since alternanthera do not do well in cold weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant alternanthera in Toronto 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 alternanthera and expect a good harvest is probably August. If you wait any later than that and your alternanthera may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your alternanthera indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Toronto. In the coldest months of winter you should expect an average low temperature of -5°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Toronto and it is different every year. Half of the time in Toronto there is a last frost after April 15 so just be sure to be ready to cover your alternanthera in the event of one of those late frosts.

USDA Zone Info for Toronto

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Toronto

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