When to Plant Osteospermum in Ontario, CA

One of the first steps you take when you are getting a good idea 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.

The USDA zone info for Ontario can be reffered to in order to determine when it's the best time to plant osteospermum.


Planting Calendar for Osteospermum

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

Since osteospermum are one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than more sensitive plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant osteospermum
Possibly ok, but a risky time to plant osteospermum
Probably not a good time to plant osteospermum

The earliest that you can plant osteospermum 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 osteospermum and expect a good harvest is probably October. Any later than that and your osteospermum may not have a chance to grow to maturity. Starting your osteospermum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Ontario. In the coldest months of winter you should expect an average low temperature of 30°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Ontario and it is different every year. Half of the time in Ontario it frosts late in the year after January 31 so always be ready to protect your osteospermum if you have one of those late frosts.

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 Low30°F
Highest Expected Low35°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.