One of the first steps you take when you are determining 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 Sterling should be looked at to figure out when 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.

Osteospermum are one of those plants that can tolerate a little bit of cold weather which means that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant osteospermum in Sterling 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. You probably don't want to wait any later than that or else your osteospermum may not have a chance to really do well. Starting your osteospermum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Sterling the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Sterling may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Sterling it frosts late in the year after April 15 be ready to protect your osteospermum in the event of one of those late frosts.

USDA Zone Info for Sterling

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 Sterling

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