The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Ottawa you can figure out when it's the best time to plant osteospermum by looking at the USDA zone info.

Planting Calendar for Osteospermum

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

Osteospermum do ok in mild cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

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

The last month that you can plant osteospermum and expect a good harvest is probably September. Any later than that and your osteospermum may not have a chance to really do well. You can get started a couple of weeks earlier by starting your osteospermum indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ottawa. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Ottawa is just an average and the actual date of last frost is different every year. Since half of the time in Ottawa there is a last frost after April 15 be ready to protect your osteospermum if you have a surprise late frost.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ottawa

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