The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when to plant osteospermum is to consult the USDA zone info for Lisle.

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 just a bit earlier in the year than more sensitive plants.

The earliest that you can plant osteospermum in Lisle 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 few weeks earlier by starting your osteospermum indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Lisle. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Lisle is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Lisle last frost occurs after April 15 so make sure that you are prepared to cover your osteospermum if you have a late frost.

USDA Zone Info for Lisle

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 Lisle

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