One of the first steps you take when you are figuring out 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.

You can estimate when it's the best time to plant oleander in Ontario by using the USDA zone info.

Planting Calendar for Oleander

Frost tolerance for oleander:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Oleander require warm weather which tells us that you need to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant oleander in Ontario 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 oleander and expect a good harvest is probably August. You probably don't want to wait any later than that or else your oleander may not have a chance to really do well. You can get started a couple of weeks earlier by starting your oleander indoors.

Last Frost Date

In Ontario the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Ontario may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Ontario you get a frost after April 15 be ready to cover your oleander in the event of a surprise late frost.

USDA Zone Info for Ontario

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 Ontario

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