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

In Rock Island you can figure out when it's possible to plant trailing portulaca by checking out the USDA zone info.

Planting Calendar for Trailing Portulaca

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

You should not plant trailing portulaca until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant trailing portulaca in Rock Island 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 trailing portulaca and expect a good harvest is probably August. If you wait any later than that and your trailing portulaca may not have a chance to really do well. You can get started a little bit earlier by starting your trailing portulaca indoors.

Last Frost Date

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

Remember that USDA zone info for Rock Island is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Rock Island last frost occurs after April 15 be ready to cover your trailing portulaca if you have one of those late frosts.

USDA Zone Info for Rock Island

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 Rock Island

You may be interested in your other planting guides for Rock Island.