Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant hosta in Ontario can be estimated by reviewing the USDA zone info.

Planting Calendar for Hosta

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

Hosta are moderately cold tolerant which tells us that you can start planting them earlier than more sensitive plants.

The earliest that you can plant hosta 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 hosta and expect a good harvest is probably October. Any later than that and your hosta may not have a chance to grow to maturity. You can get started a little bit earlier by starting your hosta indoors.

Last Frost Date

In Ontario the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Remember that USDA zone info for Ontario is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Ontario there is a last frost after January 31 so just be sure to be ready to cover your hosta in the event of a surprise 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.