One of the best tools that you have as gardeners to help us estimate 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.

In Harrisburg you can estimate when it's a good idea to plant osteospermum by checking out 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.

Since osteospermum do well in moderate cold you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant osteospermum in Harrisburg 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. If you wait any later than that and your osteospermum may not have a chance to fully mature. You can get started a few weeks earlier by starting your osteospermum indoors.

Last Frost Date

On average the last frost is on April 15 in Harrisburg. You can expect an average low temperature of 5°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Harrisburg and it can change quite a bit from year to year. Half of the time in Harrisburg you get a frost after April 15 so just be sure to be ready to cover your osteospermum if you have a surprise late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Harrisburg

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