Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Ontario it's possible to determine when you can plant lobelia.

Planting Calendar for Lobelia

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

Since lobelia are one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant lobelia in Ontario is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant lobelia and expect a good harvest is probably October. Any later than that and your lobelia may not have a chance to fully mature. You can get started a little bit earlier by starting your lobelia indoors.

Last Frost Date

On average all chance of frost has passed is on January 31 in Ontario. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Ontario is just an average the actual date of last frost changes from year to year. Since half of the time in Ontario last frost occurs after January 31 be ready to cover your lobelia in the event of a late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Ontario

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