One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when to plant osteospermum is to check out the USDA zone info for Windsor.

Planting Calendar for Osteospermum

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

Osteospermum are one of those plants that can tolerate a little bit of cold weather which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant osteospermum in Windsor 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 grow to maturity. You can get started a couple of weeks earlier by starting your osteospermum indoors.

Last Frost Date

The average date of last frost is April 15 in Windsor. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Windsor is not always accurate the actual date of last frost changes from year to year. Since half of the time in Windsor last frost occurs after April 15 be ready to cover your osteospermum in the event of a late frost.

USDA Zone Info for Windsor

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 Windsor

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