One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

You will be able to figure out when you can plant tropical hibiscus by referring to the USDA zone info for Oak Brook.

Planting Calendar for Tropical Hibiscus

Frost tolerance for tropical hibiscus:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since tropical hibiscus require warm weather you need to wait until after the last frost before you can plant them.

The earliest that you can plant tropical hibiscus in Oak Brook is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant tropical hibiscus and expect a good harvest is probably August. Any later than that and your tropical hibiscus may not have a chance to really do well. You can get started a few weeks earlier by starting your tropical hibiscus indoors.

Last Frost Date

In Oak Brook the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind 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 Oak Brook and it is different every year. Since half of the time in Oak Brook there is a last frost after April 15 be ready to cover your tropical hibiscus if you have a late frost.

USDA Zone Info for Oak Brook

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 Oak Brook

You may be interested in your other planting guides for Oak Brook.